Hubbry Logo
UrbanizationUrbanizationMain
Open search
Urbanization
Community hub
Urbanization
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Urbanization
Urbanization
Urbanization
View on Wikipedia
from Wikipedia

Global urbanization map
Global urbanization map showing the percentage of urbanization and the biggest global population centres per country in 2018, based on UN estimates.
Guangzhou, a city of 14.5 million people, is one of the 8 adjacent metropolises located in the largest single agglomeration on Earth, ringing the Pearl River Delta of China.
Mumbai is the most populous city in India, and the eighth most populous city in the world, with a total metropolitan area population of approximately 18.5 million and with the smallest area under the metropolitan of comparable cities in the world.
Moscow, the capital and largest city of Russia, is the largest metropolitan area in Europe; with over 20 million residents in its metropolitan area.
Ho Chi Minh City is the largest city in Vietnam with a population in the Ho Chi Minh metropolitan area of over 21.2 million people.

Urbanization (or urbanisation in British English) is the population shift from rural to urban areas, the corresponding decrease in the proportion of people living in rural areas, and the ways in which societies adapt to this change. It can also mean population growth in urban areas instead of rural ones.[1] It is predominantly the process by which towns and cities are formed and become larger as more people begin to live and work in central areas.[2]

Although the two concepts are sometimes used interchangeably, urbanization should be distinguished from urban growth. Urbanization refers to the proportion of the total national population living in areas classified as urban, whereas urban growth strictly refers to the absolute number of people living in those areas.[3] It is predicted that by 2050, about 64% of the developing world and 86% of the developed world will be urbanized. This is predicted to generate artificial scarcities of land, lack of drinking water, playgrounds and other essential resources for most urban dwellers.[4] The predicted urban population growth is equivalent to approximately 3 billion urbanites by 2050, much of which will occur in Africa and Asia.[5] Notably, the United Nations has also recently projected that nearly all global population growth from 2017 to 2030 will take place in cities, with about 1.1 billion new urbanites over the next 10 years.[6] In the long term, urbanization is expected to significantly impact the quality of life in negative ways.[7][8]

Urbanization is relevant to a range of disciplines, including urban planning, geography, sociology, architecture, economics, education, statistics, and public health. The phenomenon has been closely linked to globalization, modernization, industrialization, marketization, administrative/institutional power, and the sociological process of rationalization.[9][10][11] Urbanization can be seen as a specific condition at a set time (e.g. the proportion of total population or area in cities or towns), or as an increase in that condition over time. Therefore, urbanization can be quantified either in terms of the level of urban development relative to the overall population, or as the rate at which the urban proportion of the population is increasing. Urbanization creates enormous social, economic and environmental challenges, which provide an opportunity for sustainability with the "potential to use resources much less or more efficiently, to create more sustainable land use and to protect the biodiversity of natural ecosystems." However, current urbanization trends have shown that massive urbanization has led to unsustainable ways of living.[5] Developing urban resilience and urban sustainability in the face of increased urbanization is at the centre of international policy in Sustainable Development Goal 11 "Sustainable cities and communities."

Urbanization is not merely a modern phenomenon, but a rapid and historic transformation of human social roots on a global scale, whereby predominantly rural culture is being rapidly replaced by predominantly urban culture. The first major change in settlement patterns was the accumulation of hunter-gatherers into villages many thousands of years ago. Village culture is characterized by common bloodlines, intimate relationships, and communal behaviour, whereas urban culture is characterized by distant bloodlines, unfamiliar relations, and competitive behaviour. This unprecedented movement of people is forecast to continue and intensify during the next few decades, mushrooming cities to sizes unthinkable only a century ago. As a result, the world urban population growth curve has up till recently followed a quadratic-hyperbolic pattern.[12]

History

[edit]
Urbanization over the past 500 years[13]
A global map illustrating the first onset and spread of urban centres around the world, based on.[14]

From the development of the earliest cities in Indus valley civilization, Mesopotamia and Egypt until the 18th century, an equilibrium existed between the vast majority of the population who were engaged in subsistence agriculture in a rural context, and small centres of populations in the towns where economic activity consisted primarily of trade at markets and manufactures on a small scale. Due to the primitive and relatively stagnant state of agriculture throughout this period, the ratio of rural to urban population remained at a fixed equilibrium. However, a significant increase in the percentage of the global urban population can be traced in the 1st millennium BCE.[15]

With the onset of the British Agricultural Revolution and Industrial Revolution[16] in the late 18th century, this relationship was finally broken and an unprecedented growth in urban population took place over the course of the 19th century, both through continued migration from the countryside and due to the tremendous demographic expansion that occurred at that time. In England and Wales, the proportion of the population living in cities with more than 20,000 people jumped from 17% in 1801 to 54% in 1891. Moreover, and adopting a broader definition of urbanization, while the urbanized population in England and Wales represented 72% of the total in 1891, for other countries the figure was 37% in France, 41% in Prussia and 28% in the United States.[17]

As labourers were freed up from working the land due to higher agricultural productivity they converged on the new industrial cities like Manchester and Birmingham which were experiencing a boom in commerce, trade, and industry. Growing trade around the world also allowed cereals to be imported from North America and refrigerated meat from Australasia and South America. Spatially, cities also expanded due to the development of public transport systems, which facilitated commutes of longer distances to the city centre for the working class.

Urbanization rapidly spread across the Western world and, since the 1950s, it has begun to take hold in the developing world as well. At the turn of the 20th century, just 15% of the world population lived in cities.[18] According to the UN, the year 2007 witnessed the turning point when more than 50% of the world population were living in cities, for the first time in human history.[17]

Yale University in June 2016 published urbanization data from the time period 3700 BC to 2000 AD, the data was used to make a video showing the development of cities on the world during the time period.[19][20][21] The origins and spread of urban centres around the world were also mapped by archaeologists.[14]

Causes

[edit]
Population age comparison between rural Pocahontas County, Iowa and urban Johnson County, Iowa, illustrating the flight of young adults (red) to urban centres in Iowa.[22]
The City of Chicago, Illinois is an example of the early American grid system of development. The grid is enforced even on uneven topography.

Urbanization occurs either organically or planned as a result of individual, collective and state action. Living in a city can be culturally and economically beneficial since it can provide greater opportunities for access to the labour market, better education, housing, and safety conditions, and reduce the time and expense of commuting and transportation. Conditions like density, proximity, diversity, and marketplace competition are elements of an urban environment that deemed beneficial. However, there are also harmful social phenomena that arise: alienation, stress, increased cost of living, and mass marginalization that are connected to an urban way of living.[citation needed] Suburbanization, which is happening in the cities of the largest developing countries, may be regarded as an attempt to balance these harmful aspects of urban life while still allowing access to the large extent of shared resources.[citation needed]

In cities, money, services, wealth and opportunities are centralized. Many rural inhabitants come to the city to seek their fortune and alter their social position. Businesses, which provide jobs and exchange capital, are more concentrated in urban areas. Whether the source is trade or tourism, it is also through the ports or banking systems, commonly located in cities, that foreign money flows into a country.

Many people move into cities for economic opportunities, but this does not fully explain the very high recent urbanization rates in places like China and India. Rural flight is a contributing factor to urbanization. In rural areas, often on small family farms or collective farms in villages, it has historically been difficult to access manufactured goods, though the relative overall quality of life is very subjective, and may certainly surpass that of the city. Farm living has always been susceptible to unpredictable environmental conditions, and in times of drought, flood or pestilence, survival may become extremely problematic.

Thai farmers are seen as poor, stupid, and unhealthy. As young people flee the farms, the values and knowledge of rice farming and the countryside are fading, including the tradition of long kek, helping neighbours plant, harvest, or build a house. We are losing what we call Thai-ness, the values of being kind, helping each other, having mercy and gratefulness.
– Iam Thongdee, Professor of Humanities, Mahidol University in Bangkok[23]

In a New York Times article concerning the acute migration away from farming in Thailand, life as a farmer was described as "hot and exhausting". "Everyone says the farmer works the hardest but gets the least amount of money". In an effort to counter this impression, the Agriculture Department of Thailand is seeking to promote the impression that farming is "honorable and secure".[23]

However, in Thailand, urbanization has also resulted in massive increases in problems such as obesity. Shifting from a rural environment to an urbanized community also caused a transition to a diet that was mainly carbohydrate-based to a diet higher in fat and sugar, consequently causing a rise in obesity.[24][better source needed] City life, especially in modern urban slums of the developing world, is not immune to pestilence or climatic disturbances such as floods, yet continues to strongly attract migrants. Examples of this were the 2011 Thailand floods and 2007 Jakarta flood. Urban areas are also far more prone to violence, drugs, and other urban social problems. In the United States, industrialization of agriculture has negatively affected the economy of small and middle-sized farms and strongly reduced the size of the rural labor market.

These are the costs of participating in the urban economy. Your increased income is canceled out by increased expenditure. In the end, you have even less left for food.
– Madhura Swaminathan, economist at Kolkata's Indian Statistical Institute[25]

Particularly in the developing world, conflict over land rights due to the effects of globalization has led to less politically powerful groups, such as farmers, losing or forfeiting their land, resulting in obligatory migration into cities. In China, where land acquisition measures are forceful, there has been far more extensive and rapid urbanization (54%) than in India (36%), where peasants form militant groups (e.g. Naxalites) to oppose such efforts. Obligatory and unplanned migration often results in the rapid growth of slums. This is also similar to areas of violent conflict, where people are driven off their land due to violence.

Cities offer a larger variety of services, including specialist services not found in rural areas. These services require workers, resulting in more numerous and varied job opportunities. Elderly people may be forced to move to cities where there are doctors and hospitals that can cater to their health needs. Varied and high-quality educational opportunities are another factor in urban migration, as well as the opportunity to join, develop, and seek out social communities.

Urbanization also creates opportunities for women that are not available in rural areas. This creates a gender-related transformation where women are engaged in paid employment and have access to education. This may cause fertility to decline. However, women are sometimes still at a disadvantage due to their unequal position in the labour market, their inability to secure assets independently from male relatives and exposure to violence.[26]

People in cities are more productive than in rural areas. An important question is whether this is due to agglomeration effects or whether cities simply attract those who are more productive. Urban geographers have shown that there exists a large productivity gain due to locating in dense agglomerations. It is thus possible that agents locate in cities in order to benefit from these agglomeration effects.[27]

Dominant conurbation

[edit]
See also: List of largest cities throughout history and Primate city

The dominant conurbation(s) of a country can get more benefits from the same things cities offer, attracting the rural population and urban and suburban populations from other cities. Dominant conurbations are quite often disproportionately large cities, but do not have to be. For instance Greater Manila is a conurbation instead of a city. Its total population of 20 million (over 20% national population) make it a primate city, but Quezon City (2.7 million), the largest municipality in Greater Manila, and Manila (1.6 million), the capital, are normal cities instead. A conurbation's dominance can be measured by output, wealth, and especially population, each expressed as a percentage of the entire country's. Greater Seoul is one conurbation that dominates South Korea. It is home to 50% of the entire national population.[28]

Though Greater Busan-Ulsan (15%, 8 million) and Greater Osaka (14%, 18 million) dominate their respective countries, their populations are moving to their even more dominant rivals, Seoul and Tokyo respectively.[29]

Economic effects

[edit]
A crowded BTS Station during the rush hour in Bangkok, Thailand
Gross domestic product per capita and level of urbanization

As cities develop, costs will skyrocket. This often takes the working class out of the market, including officials and employees of the local districts. For example, Eric Hobsbawm's book The age of revolution: 1789–1848 (published 1962 and 2005) chapter 11, stated "Urban development in our period was a gigantic process of class segregation, which pushed the new labouring poor into great morasses of misery outside the centres of government, business, and the newly specialized residential areas of the bourgeoisie. The almost universal European division into a 'good' west end and a 'poor' east end of large cities developed in this period." This is probably caused by the south-west wind which carries coal smoke and other pollutants down, making the western edges of towns better than the eastern ones.[30]

Similar problems now affect less developed countries, as rapid development of cities makes inequality worse. The drive to grow quickly and be efficient can lead to less fair urban development. Think tanks such as the Overseas Development Institute have proposed policies that encourage labour-intensive to make use of the migration of less skilled workers.[31] One problem these migrant workers are involved with is the growth of slums. In many cases, the rural-urban unskilled migrant workers are attracted by economic opportunities in cities. Unfortunately, they cannot find a job and or pay for houses in urban areas and have to live in slums.[32]

Urban problems, along with developments in their facilities, are also fuelling suburb development trends in less developed nations, though the trend for core cities in said nations tends to continue to become ever denser. Development of cities is often viewed negatively, but there are positives in cutting down on transport costs, creating new job opportunities, providing education and housing, and transportation. Living in cities permits individuals and families to make use of their closeness to workplaces and diversity.[33][34][35][36] While cities have more varied markets and goods than rural areas, facility congestion, domination of one group, high overhead and rental costs, and the inconvenience of trips across them frequently combine to make marketplace competition harsher in cities than in rural areas.[citation needed]

In many developing countries where economies are growing, the growth is often random and based on a small number of industries. Youths in these nations lack access to financial services and business advisory services, cannot get credit to start a business, and have no entrepreneurial skills. Therefore, they cannot seize opportunities in these industries. Making sure adolescents have access to excellent schools and infrastructure to work in such industries and improve schools is compulsory to promote a fair society.[37]

Environmental effects

[edit]
Part of a series on
Pollution
Air pollution from a factory
Air
Biological
Digital
Electromagnetic
Natural
Noise
Radiation
Soil
Solid waste
Space
Thermal
Visual
War
Water
Topics
Misc
Lists
Categories

Furthermore, urbanization improves environmental eminence through superior facilities and standards in urban areas as compared to rural areas. Lastly, urbanization curbs pollution emissions by increasing innovations.[38] In his 2009 book Whole Earth Discipline, Stewart Brand argues that the effects of urbanization are primarily positive for the environment. First, the birth rate of new urban dwellers falls immediately to replacement rate and keeps falling, reducing environmental stresses caused by population growth.[39] Secondly, emigration from rural areas reduces destructive subsistence farming techniques, such as improperly implemented slash and burn agriculture. Alex Steffen also speaks of the environmental benefits of increasing the urbanization level in "Carbon Zero: Imagining Cities that can save the planet".[40]

However, existing infrastructure and city planning practices are not sustainable.[41] In July 2013 a report issued by the United Nations Department of Economic and Social Affairs[42] warned that with 2.4 billion more people by 2050, the amount of food produced will have to increase by 70%, straining food resources, especially in countries already facing food insecurity due to changing environmental conditions. The mix of changing environmental conditions and the growing population of urban regions, according to UN experts, will strain basic sanitation systems and health care, and potentially cause a humanitarian and environmental disaster.[43]

Urban heat island

[edit]

Urban heat islands have become a growing concern over the years. An urban heat island is formed when industrial areas absorb and retain heat. Much of the solar energy reaching rural areas is used to evaporate water from plants and soil. In cities, there are less vegetation and exposed soil. Most of the sun's energy is instead absorbed by buildings and asphalt; leading to higher surface temperatures. Vehicles, factories, and heating and cooling units in factories and homes release even more heat.[44] As a result, cities are often 1 to 3 °C (1.8 to 5.4 °F) warmer than other areas near them.[45] Urban heat islands also make the soil drier and absorb less carbon dioxide from emissions.[46] A Qatar University study found that land-surface temperatures in Doha increased annually by 0.65 °C from 2002 to 2013 and 2023.[47]

Water quality

[edit]

Urban runoff, polluted water created by rainfall on impervious surfaces, is a common effect of urbanization. Precipitation from rooftops, roads, parking lots and sidewalks flows to storm drains, instead of percolating into groundwater. The contaminated stormwater in the drains is typically untreated and flows to nearby streams, rivers or coastal bays.[48]

Eutrophication in water bodies is another effect large populations in cities have on the environment. When rain occurs in these large cities, it filters CO2 and other pollutants in the air onto the ground. These chemicals are washed directly into rivers, streams, and oceans, making water worse and damaging ecosystems in them.[49]

Eutrophication is a process which causes low levels of oxygen in water and algal blooms that may harm aquatic life.[50] Harmful algal blooms make dangerous toxins. They live best in nitrogen- and phosphorus-rich places which include the oceans contaminated by the aforementioned chemicals.[51] In these ideal conditions, they choke surface water, blocking sunlight and nutrients from other life forms. Overgrowth of algal blooms makes water worse overall and disrupts the natural balance of aquatic ecosystems. Furthermore, as algal blooms die, CO2 is produced. This makes the ocean more acidic, a process called acidification.[52]

The ocean's surface can absorb CO2 from the Earth's atmosphere as emissions increase with the rise in urban development. In fact, the ocean absorbs a quarter of the CO2 produced by humans.[53] This helps to lessen the harmful effects of greenhouse gases, but it also makes the ocean more acidic.[54] A drop in pH the prevents the proper formation of calcium carbonate, which sea creatures need to build or keep shells or skeletons.[55][53] This is especially true for many species of molluscs and coral. However, some species have been able to thrive in a more acidic environment.[56]

Food waste

[edit]

Rapid growth of communities creates new challenges in the developed world and one such challenge is an increase in food waste[57] also known as urban food waste.[58][59][60] Food waste is the disposal of food products that can no longer be used due to unused products, expiration, or spoilage. The increase of food waste can raise environmental concerns such as increase production of methane gases and attraction of disease vectors.[59][61] Landfills are the third leading cause of the release of methane,[62] causing a concern on its impact to our ozone and on the health of individuals. Accumulation of food waste causes increased fermentation, which increases the risk of rodent and bug migration. An increase in migration of disease vectors creates greater potential of disease spreading to humans.[63]

Waste management systems vary on all scales from global to local and can also be influenced by lifestyle. Waste management was not a primary concern until after the Industrial Revolution. As urban areas continued to grow along with the human population, proper management of solid waste became an apparent concern. To address these concerns, local governments sought solutions with the lowest economic impacts which meant implementing technical solutions at the very last stage of the process.[64] Current waste management reflects these economically motivated solutions, such as incineration or unregulated landfills. Yet, a growing increase for addressing other areas of life cycle consumption has occurred from initial stage reduction to heat recovery and recycling of materials.[64] For example, concerns for mass consumption and fast fashion have moved to the forefront of the urban consumers' priorities. Aside from environmental concerns (e.g. climate change effects), other urban concerns for waste management are public health and land access.

Habitat fragmentation

[edit]

Urbanization can have a large effect on biodiversity by causing a division of habitats and thereby alienation of species, a process known as habitat fragmentation.[65] Habitat fragmentation does not destroy the habitat, as seen in habitat loss, but rather breaks it apart with things like roads and railways.[66] This change may affect a species ability to sustain life by separating it from the environment in which it is able to easily access food, and find areas that they may hide from predation.[67] With proper planning and management, fragmentation can be avoided by adding corridors that aid in the connection of areas and allow for easier movement around urbanized regions.[68][69]

Depending on the various factors, such as level of urbanization, both increases or decreases in "species richness" can be seen.[70][71] This means that urbanization may be detrimental to one species but also help facilitate the growth of others. In instances of housing and building development, many times vegetation is completely removed immediately in order to make it easier and less expensive for construction to occur, thereby obliterating any native species in that area. Habitat fragmentation can filter species with limited dispersal capacity. For example, aquatic insects are found to have lower species richness in urban landscapes.[72] The more urbanized the surrounding of habitat is, the fewer species can reach the habitat.[73] The negative effects of urbanisation on aquatic insects can be long-lasting from the temporal perspective.[74] Other times, such as with birds, urbanization may allow for an increase in richness when organisms are able to adapt to the new environment. This can be seen in species that may find food while scavenging developed areas or vegetation that has been added after urbanization has occurred i.e. planted trees in city areas.[75]

Health and social effects

[edit]
When cities don't plan for increases in population it drives up house and land prices, creating rich (ghettos) and poor ghettos. "You get a very unequal society and that inequality is manifested where people live, in our neighbourhoods, and it means there can be less capacity for empathy and less development for all society."
– Jack Finegan, Urban Programme Specialist at UN-Habitat[76]

In the developing world, urbanization does not translate into a significant increase in life expectancy.[77] Rapid urbanization has led to increased mortality from non-communicable diseases associated with lifestyle, including cancer and heart disease.[78] Differences in mortality from contagious diseases vary depending on the particular disease and location.[77]

Urban health levels are on average better in comparison to rural areas. However, residents in poor urban areas such as slums and informal settlements suffer "disproportionately from disease, injury, premature death, and the combination of ill-health and poverty entrenches disadvantage over time."[26] Many of the urban poor have difficulty accessing health services due to their inability to pay for them; so they resort to less qualified and unregulated providers.[citation needed]

While urbanization is associated with improvements in public hygiene, sanitation and access to health care, it also entails changes in occupational, dietary, and exercise patterns.[78] It can have mixed effects on health patterns, alleviating some problems, and accentuating others.[77]

Nutrition

[edit]

Traditionally, rural populations have tended to eat plant-based diets rich in grains, fruits and vegetables, and with low fat content. However, rural people migrating to urban areas often shift towards diets that rely more on processed foods characterized by a higher content of meat, sugars, refined grains and fats. Urban residents typically have reduced time available for at-home food preparation combined with increased disposable income, facilitating access to convenience foods and ready-to-eat meals.[79]

One such effect is the formation of food deserts. Nearly 23.5 million people in the United States lack access to supermarkets within one mile of their home.[80] Several studies suggest that long distances to a grocery store are associated with higher rates of obesity and other health disparities.[81]

Food deserts in developed countries often correspond to areas with a high density of fast food chains and convenience stores that offer little to no fresh food.[82] Urbanization has been shown to be associated with the consumption of less fresh fruits, vegetables, and whole grains and a higher consumption of processed foods and sugar-sweetened beverages.[81] Poor access to healthy food and high intakes of fat, sugar and salt are associated with a greater risk for obesity, diabetes and related chronic disease. Overall, body mass index and cholesterol levels increase sharply with national income and the degree of urbanization.[40]

Food deserts in the United States are most commonly found in low-income and predominately African American neighbourhoods.[81] One study on food deserts in Denver, Colorado found that, in addition to minorities, the affected neighbourhoods also had a high proportion of children and new births.[83] In children, urbanization is associated with a lower risk of under-nutrition but a higher risk of being overweight.[77]

Infections

[edit]

Urbanization has also been linked to the spread of communicable diseases, which can spread more rapidly in the favourable environment with more people living in a smaller area. Such diseases can be respiratory infections and gastrointestinal infections. Other infections could be infections, which need a vector to spread to humans. An example of this could be dengue fever.[84]

Asthma

[edit]

Urbanization has also been associated with an increased risk of asthma as well. Throughout the world, as communities transition from rural to more urban societies, the number of people affected by asthma increases. The odds of reduced rates of hospitalization and death from asthmas has decreased for children and young adults in urbanized municipalities in Brazil. This finding indicates that urbanization may have a negative impact on population health particularly affecting people's susceptibility to asthma.[85]

In low and middle income countries many factors contribute to the high numbers of people with asthma. Similar to areas in the United States with increasing urbanization, people living in growing cities in low income countries experience high exposure to air pollution, which increases the prevalence and severity of asthma among these populations.[86] Links have been found between exposure to traffic-related air pollution and allergic diseases.[87] Children living in poor, urban areas in the United States now have an increased risk of morbidity due to asthma in comparison to other low-income children in the United States.[88] In addition, children with croup living in urban areas have higher hazard ratios for asthma than similar children living in rural areas. Researchers suggest that this difference in hazard ratios is due to the higher levels of air pollution and exposure to environmental allergens found in urban areas.[89]

Exposure to elevated levels of ambient air pollutants such as nitrogen dioxide (NO2), carbon monoxide (CO), and particulate matter with a diameter of less than 2.5 micrometres (PM2.5), can cause DNA methylation of CpG sites in immune cells, which increases children's risk of developing asthma. Studies have shown a positive correlation between Foxp3 methylation and children's exposure to NO2, CO, and PM2.5. Furthermore, any amount of exposure to high levels of air pollution have shown long term effects on the Foxp3 region.[90]

Despite the increase in access to health services that usually accompanies urbanization, the rise in population density negatively affects air quality ultimately mitigating the positive value of health resources as more children and young adults develop asthma due to high pollution rates.[85] However, urban planning, as well as emission control, can lessen the effects of traffic-related air pollution on allergic diseases such as asthma.[87]

Crime

[edit]

Historically, crime and urbanization have gone hand in hand. The simplest explanation is that areas with a higher population density are surrounded by greater availability of goods. Committing crimes in urbanized areas is also more feasible. Modernization has led to more crime as well, as the modern media has raised greater awareness of the income gap between the rich and the poor. This leads to feelings of deprivation, which in turn can lead to crime. In some regions where urbanization happens in wealthier areas, a rise in property crime and a decrease in violent crime is seen.[91]

Data shows that there is an increase in crime in urbanized areas. Some factors include per capita income, income inequality, and overall population size. There is also a smaller association between unemployment rate, police expenditures and crime.[92] The presence of crime also has the ability to produce more crime. These areas have less social cohesion and therefore less social control. This is evident in the geographical regions that crime occurs in. As most crime tends to cluster in city centres, the further the distance from the centre of the city, the lower the occurrence of crimes are.[93]

Migration is also a factor that can increase crime in urbanized areas. People from one area are displaced and forced to move into an urbanized society. Here they are in a new environment with new norms and social values. This can lead to less social cohesion and more crime.[94]

Physical activity

[edit]

Although urbanization tends to produce more negative effects, one positive effect that urbanization has impacted is an increase in physical activity in comparison to rural areas. Residents of rural areas and communities in the United States have higher rates of obesity and engage in less physical activity than urban residents.[95] Rural residents consume a higher percent of fat calories and are less likely to meet the guidelines for physical activity and more likely to be physically inactive.[96][97] In comparison to regions within the United States, the west has the lowest prevalence of physical inactivity and the south has the highest prevalence of physical inactivity.[97] Metropolitan and large urban areas across all regions have the highest prevalence of physical activity among residents.[97]

Barriers such as geographic isolation, busy and unsafe roads, and social stigmas lead to decreased physical activity in rural environments.[98] Faster speed limits on rural roads prohibits the ability to have bike lanes, sidewalks, footpaths, and shoulders along the side of the roads.[95] Less developed open spaces in rural areas, like parks and trails, suggest that there is lower walkability in these areas in comparison to urban areas.[95] Many residents in rural settings have to travel long distances to utilize exercise facilities, taking up too much time in the day and deterring residents from using recreational facilities to obtain physical activity.[98] Additionally, residents of rural communities are traveling further for work, decreasing the amount of time that can be spent on leisure physical activity and significantly decreases the opportunity to partake in active transportation to work.[95]

Neighbourhoods and communities with nearby fitness venues, a common feature of urbanization, have residents that partake in increased amounts of physical activity.[98] Communities with sidewalks, street lights, and traffic signals have residents participating in more physical activity than communities without those features.[95] Having a variety of destinations close to where people live, increases the use of active transportation, such as walking and biking.[99] Active transportation is also enhanced in urban communities where there is easy access to public transportation due to residents walking or biking to transportation stops.[99]

In a study comparing different regions in the United States, opinions across all areas were shared that environmental characteristics like access to sidewalks, safe roads, recreational facilities, and enjoyable scenery are positively associated with participation in leisure physical activity.[97] Perceiving that resources are nearby for physical activity increases the likelihood that residents of all communities will meet the guidelines and recommendations for appropriate physical activity.[99] Specific to rural residents, the safety of outdoor developed spaces and convenient availability to recreational facilities matters most when making decisions on increasing physical activity.[96] In order to combat the levels of inactivity in rural residents, more convenient recreational features, such as the ones discussed in this paragraph, need to be implemented into rural communities and societies.[citation needed]

Mental health

[edit]

Urbanization factors that contribute to mental health can be thought of as factors that affect the individual and factors that affect the larger social group. At the macro, social group level, changes related to urbanization are thought to contribute to social disintegration and disorganization. These macro factors contribute to social disparities which affect individuals by creating perceived insecurity.[100] Perceived insecurity can be due problems with the physical environment, such as issues with personal safety, or problems with the social environment, such as a loss of positive self-concepts from negative events.[101] Increased stress is a common individual psychological stressor that accompanies urbanization and is thought to be due to perceived insecurity. Changes in social organization, a consequence of urbanization, are thought to lead to reduced social support, increased violence, and overcrowding. It is these factors that are thought to contribute to increased stress.[102]

A 2004 study of 4.4 million Swedish residents found that people who live in cities have a 20% increased chance of developing depression[need quotation to verify].[103]

Changing forms

[edit]
Patterns of urbanization

Different forms of urbanization can be classified depending on the style of architecture and planning methods as well as the historic growth of areas.

Map showing urban areas with at least one million inhabitants in 2020.

In cities of the developed world urbanization traditionally exhibited a concentration of human activities and settlements around the downtown area, the so-called in-migration. In-migration refers to migration from former colonies and similar places. The fact that many immigrants settle in impoverished city centres led to the notion of the "peripheralization of the core", which simply describes that people who used to be at the periphery of the former empires now live right in the centre.

Recent developments, such as inner-city redevelopment schemes, mean that new arrivals in cities no longer necessarily settle in the centre. In some developed regions, the reverse effect, originally called counter urbanization has occurred, with cities losing population to rural areas, and is particularly common for richer families. This has been possible because of improved communications and has been caused by factors such as the fear of crime and poor urban environments. It has contributed to the phenomenon of shrinking cities experienced by some parts of the industrialized world.

Rural migrants are attracted by the possibilities that cities can offer, but often settle in shanty towns and experience extreme poverty. The inability of countries to provide adequate housing for these rural migrants is related to overurbanization, a phenomenon in which the rate of urbanization grows more rapidly than the rate of economic development, leading to high unemployment and high demand for resources.[104] In the 1980s, this was attempted to be tackled with the urban bias theory which was promoted by Michael Lipton.

Most of the urban poor in developing countries unable to find work can spend their lives in insecure, poorly paid jobs. According to research by the Overseas Development Institute pro-poor urbanization will require labour-intensive growth, supported by labour protection, flexible land use regulation and investments in basic services.'[105]

Suburbanization

[edit]
Main article: Suburbanization

When the residential area shifts outward, this is called suburbanization. A number of researchers and writers suggest that suburbanization has gone so far to form new points of concentration outside the downtown both in developed and developing countries such as India.[106] This networked, poly-centric form of concentration is considered by some emerging pattern of urbanization. It is called variously edge city (Garreau, 1991), network city (Batten, 1995), postmodern city (Dear, 2000), or exurb, though the latter term now refers to a less dense area beyond the suburbs. Los Angeles is the best-known example of this type of urbanization. In the United States, this process has reversed as of 2011, with "re-urbanization" occurring as suburban flight due to chronically high transport costs.[107]

...the most important class conflict in the poor countries of the world today is not between labour and capital. Nor is it between foreign and national interests. It is between rural classes and urban classes. The rural sector contains most of the poverty and most of the low-cost sources of potential advance; but the urban sector contains most of the articulateness, organization, and power. So the urban classes have been able to win most of the rounds of the struggle with the countryside...
– Michael Lipton, author of urban bias theory[108]

Planned urbanization

[edit]

Urbanization can be planned urbanization or organic. Planned urbanization, i.e.: planned community or the garden city movement, is based on an advance plan, which can be prepared for military, aesthetic, economic or urban design reasons. Examples can be seen in many ancient cities; although with exploration came the collision of nations, which meant that many invaded cities took on the desired planned characteristics of their occupiers. Many ancient organic cities experienced redevelopment for military and economic purposes, new roads carved through the cities, and new parcels of land were cordoned off serving various planned purposes giving cities distinctive geometric designs. UN agencies prefer to see urban infrastructure installed before urbanization occurs. Landscape planners are responsible for landscape infrastructure (public parks, sustainable urban drainage systems, greenways etc.) which can be planned before urbanization takes place, or afterwards to revitalize an area and create greater livability within a region. Concepts of control of the urban expansion are considered in the American Institute of Planners.

As population continues to grow and urbanize at unprecedented rates, new urbanism and smart growth techniques are implemented to create a transition into developing environmentally, economically, and socially sustainable cities. Additionally, a more well-rounded approach articulates the importance to promote participation of non-state actors, which could include businesses, research and non-profit organizations and, most importantly, local citizens.[109] Smart Growth and New Urbanism's principles include walkability, mixed-use development, comfortable high-density design, land conservation, social equity, and economic diversity. Mixed-use communities work to fight gentrification with affordable housing to promote social equity, decrease automobile dependency to lower use of fossil fuels, and promote a localized economy. Walkable communities have a 38% higher average GDP per capita than less walkable urban metros (Leinberger, Lynch). By combining economic, environmental, and social sustainability, cities will become equitable, resilient, and more appealing than urban sprawl that overuses land, promotes automobile use, and segregates the population economically.[110][111]

Water scarcity

[edit]
This section is an excerpt from Water stress and urbanization.[edit]
Water stress is increasingly affecting urbanization. Water stress arises through slum development, anarchic construction, water scarcity, the absence of financial structures, the absence of basic structures, the absence of infrastructure such as roads, bridges, sidewalks, signs, markets, schools, etc., can sometimes hinder the productivity of certain cities. Unfortunately, this phenomenon affects even the largest cities in the world; in 2018, 300,000 were recorded in the world, housing around 40% of the world's urban population.[112]

Urbanization throughout the world

[edit]
Main article: Urbanization by sovereign state
Map with circled African and Asian belts of non-urbanized countries

Presently, most countries in the world are urbanized, with the global urbanization average numbering 56.2% in 2020.[113] However, there are great differences between some regions; the nations of Europe, the Middle East, the Americas and East Asia are predominantly urbanized. Meanwhile, two large belts (from central to eastern Africa, and from central to southeast Asia) of very lowly urbanized countries exist, as seen on the map here. These labeled countries are among the least urbanized.[citation needed]

As of 2022, urbanization rates are over 80% in the United States, Canada, Mexico, Brazil, Argentina, Chile, Japan, Australia, the United Kingdom, France, Finland, Denmark, Israel, Spain and South Korea. South America is the most urbanized continent in the world, accounting for more than 80% of its total population living in urban areas. It is also the only continent where the urbanization rate is over 80%.

See also

[edit]

Historical

[edit]

Regional

[edit]

References

[edit]

Sources

[edit]

Further reading

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Urbanization

View on Grokipedia
from Grokipedia
Urbanization is the progressive concentration of human populations into urban areas, characterized by rural-to-urban migration, the expansion of built environments, and the densification of economic and social activities within cities. This phenomenon has intensified over the past two centuries, with the share of the global population living in urban settings rising from approximately 3% in 1800 to over 55% today, encompassing more than 4 billion individuals. Principally propelled by in that liberates labor for industrial and service sectors, alongside pull factors like higher wages and amenities in cities, urbanization correlates strongly with and growth. It has enabled unprecedented advancements in productivity, , and , yet concurrently generates pressures including , resource strain, and uneven spatial development, especially in low-income countries where informal settlements proliferate. projections forecast that urban dwellers will constitute 68% of the world population by 2050, with the bulk of future urban expansion in and , necessitating adaptive governance to harness benefits while mitigating externalities.

Definition and Conceptual Framework

Core Definition and Etymology

Urbanization refers to the increasing concentration of populations in urban areas, characterized by the expansion of cities, towns, and settlements through demographic shifts, land-use transformation from rural to built environments, and associated economic activities. This process entails not only in discrete urban locales but also changes in settlement , development, and the reorganization of social and economic functions away from dispersed rural patterns. Scholarly analyses emphasize that urbanization involves both absolute increases in urban dwellers—driven by natural and net migration—and relative rises in the urban share of total , often measured against rural baselines. The term originates from the Latin urbs, denoting a or enclosed settlement, which forms the root of urbanus ("pertaining to the ") and evolved through into modern usage. "Urbanization" as a emerged in English by the , derived from "urbanize" (first attested in the 1640s meaning "to make civil" but shifting by 1884 to "convert into a ," influenced by French urbaniser from 1873), with the "-ation" indicating the act or process. This linguistic development reflects historical observations of societal transitions toward centralized, -based living, distinct from earlier agrarian dispersals.

Measurement Metrics and Urban-Rural Dichotomy

Urbanization is commonly measured by the percentage of a country's total residing in urban areas, a metric tracked by organizations such as the and the World Bank using national data and estimates. This proportion reflects the shift from rural to urban living but relies on varying national definitions of "urban," which complicates cross-country comparisons. Additional metrics include urban growth rates, the number of urban agglomerations exceeding certain population thresholds (e.g., one million inhabitants), and density-based indicators like built-up area coverage from satellite data. Definitions of urban areas diverge significantly across countries and institutions, often incorporating thresholds for population size, density, economic function, or administrative status. For instance, the classifies urbanized areas as contiguous blocks with at least 50,000 residents and urban clusters as those with 2,500 to 49,999 residents, emphasizing contiguous high-density settlement. In contrast, countries like use administrative designations, while others, such as , apply low population thresholds (e.g., 200 inhabitants) combined with centrality measures. The World Bank generally adopts national statistical offices' criteria for urban population percentages but employs grid-based approaches—such as 250-meter cells with over 50% built-up area—for more consistent global analyses, highlighting how administrative boundaries can inflate or deflate reported urbanization levels. To address definitional inconsistencies, the endorsed the Degree of Urbanisation method in March 2020, classifying global territories into three categories based on and : cities (50,000+ inhabitants at >1,500 people/km²), towns and semi-dense areas (5,000–49,999 inhabitants at 300–1,500 people/km²), and rural areas (fewer than 5,000 inhabitants or <300 people/km²). This gridded, harmonized approach uses census and satellite data to enable comparable metrics, revealing that national definitions can vary urban population shares by up to 20–30 percentage points in some cases. Despite its advantages, implementation requires high-quality geospatial data, which remains limited in developing regions. The urban-rural dichotomy underpinning these metrics oversimplifies settlement patterns, as real-world transitions form continua with peri-urban zones exhibiting mixed characteristics like commuting flows and hybrid land uses. This binary classification struggles to capture functional integration, where rural areas supply labor and resources to cities, and urban sprawl encroaches on countryside, leading to measurement challenges such as double-counting migrants or ignoring suburban density gradients. Critics argue it masks intra-rural or intra-urban disparities and fails to track subtle urbanicity changes over time, prompting calls for multidimensional indices incorporating infrastructure access or economic output alongside demographics. Empirical studies using continuum models, such as those scaling urbanicity by remoteness from city centers, demonstrate stronger correlations with development outcomes than strict dichotomies.
Criterion TypeExamples of Definitions
Population ThresholdSweden: ≥200 inhabitants; India: ≥5,000 with specific density/economic criteria; United States: ≥50,000 for urbanized areas.
Density-FocusedUN Degree: >1,500/km² for cities; World Bank grids: >50% built-up in 250m cells.
Administrative/Hybrid: Legally designated cities; Many African nations: Government gazetted towns regardless of size.

Historical Development

Ancient and Pre-Industrial Urban Centers

The origins of urbanization trace to southern during the , circa 4000–3100 BCE, where the city of expanded to approximately 250 hectares by 3100 BCE and later achieved a population of around 50,000 inhabitants through intensified , irrigation systems, and centralized administration. This development featured monumental ziggurats, temple complexes, and evidence of craft specialization, enabling surplus production that supported non-agricultural elites and laborers. Parallel urban formations arose independently in the Indus Valley around 2600 BCE, with and demonstrating grid-based planning, baked-brick architecture, and sophisticated drainage, sustaining estimated populations of 30,000 to 60,000 each via riverine and . In , Memphis emerged as the primary urban center circa 3100 BCE, serving as the capital of unified and concentrating governmental, religious, and economic functions, though its population likely remained below 50,000 due to reliance on flood-based farming and decentralized villages. Early Chinese urbanization manifested at Erlitou (c. – BCE), a 300-hectare site with foundations, bronze workshops, and ritual areas, indicating state-level organization possibly tied to proto-dynastic polities and supporting several thousand residents through millet and rice cultivation. Further north, functioned as the capital from approximately 1300 to 1046 BCE, encompassing oracle bone inscriptions, royal tombs, and artisan quarters for a population exceeding 10,000. Mesoamerican urbanization lagged, with rising by the 1st century CE to cover 20 square kilometers and house over 100,000 people in multi-ethnic neighborhoods, pyramids, and marketplaces, fueled by and agriculture despite lacking draft animals or iron tools. Pre-industrial cities worldwide, spanning these ancient hubs to medieval exemplars like (peaking at 500,000 residents in the 6th century CE via Black Sea commerce) and (nearing 1 million in the Abbasid era through canal-irrigated hinterlands), typically comprised less than 10% of regional populations, dependent on rural surpluses transported by or labor. These centers centralized power, , and exchange but faced constraints from , , and limited , often stagnating below 100,000 inhabitants until technological advances.

Industrial Era Acceleration

The , commencing in Britain during the late , catalyzed a sharp acceleration in urbanization by concentrating mechanized production and labor in emerging industrial hubs proximate to resources, waterways, and ports. This shift drew rural populations to cities seeking wage labor in factories, where steam-powered machinery enabled unprecedented scales of output unattainable in dispersed agrarian settings. In , the urban population share—defined as residents in settlements exceeding 2,500 inhabitants—rose from approximately 20% in 1800 to over 50% by 1851, reflecting net in-migration exceeding natural in urban areas. Agricultural enclosures, formalized through parliamentary acts peaking between 1760 and 1820, played a pivotal causal role by consolidating fragmented common lands into larger, privately held farms optimized for and livestock improvement, thereby displacing smallholders and cottagers reliant on communal access for subsistence. These reforms boosted agricultural yields by an average of 45% in enclosed parishes by 1830, freeing surplus labor from the countryside while exacerbating rural inequality and , which funneled migrants toward urban opportunities. from parish-level indicates that enclosed regions experienced heightened out-migration rates, with many former rural laborers absorbing into mills and , as urban industrial wages, though initially low, offered higher returns than declining agrarian prospects. exemplifies this dynamic: its population surged from 77,000 in 1801 to 316,000 by 1851, driven primarily by influxes that tripled the local populace over the first half of the century. The pattern propagated across continental Europe and North America as industrial technologies diffused, with Belgium achieving early mechanization around 1830 and Germany following via Ruhr Valley coal fields, elevating Europe's overall urban share from under 15% in 1800 to about 25% by 1900 in industrializing nations. In the United States, urbanization lagged initially due to abundant land but accelerated post-1840 with railroad expansion and immigrant labor inflows, propelling the urban population from 5% in 1800 to 40% by 1900, concentrated in manufacturing corridors like the Northeast. Infrastructure innovations, including canals and later steam railroads, reduced transport costs by up to 80% for bulk goods, further incentivizing urban agglomeration by linking factories to raw materials and markets. This era's urbanization, however, imposed immediate strains, including overcrowded housing and sanitation deficits, as city populations outpaced infrastructural adaptation. ![Urbanization trends over time](./assets/Urbanization_over_the_past_500_years_(Historical_sources_and_UN_(1500_to_2016))

20th Century Suburbanization and Global Spread

In the United States, suburbanization intensified after World War II, fueled by widespread automobile adoption, the Federal-Aid Highway Act of 1956 which funded over 40,000 miles of interstate highways, and federal policies like the GI Bill and FHA loans that enabled low-cost homeownership for returning veterans and middle-class families. The suburban share of the U.S. population increased from 19.5% in 1940 to 30.7% by 1960, coinciding with a rise in homeownership from 44% to 62%. Developments such as Levittown, New York—where prefabricated homes were produced at a rate of 30 per day starting in 1947—exemplified mass-produced, single-family housing that attracted over 82,000 residents across Levittown sites by the early 1950s, driven by the baby boom generation's demand for spacious living away from urban density. This shift also reflected racial dynamics, with white middle-class families moving outward amid urban deindustrialization and policies like redlining that restricted minority access to suburban loans, though Black suburbanization grew modestly to about 5% of the Black population by 1960. ![Urbanization trends over the past 500 years](./assets/Urbanization_over_the_past_500_years_(Historical_sources_and_UN_(1500_to_2016)) In Europe, suburbanization emerged more gradually and was constrained by postwar reconstruction priorities, denser land use, and zoning laws favoring compact development, though automobile growth and peripheral housing projects accelerated sprawl from the 1960s onward. By 1990, many large European cities experienced substantial outward migration, with central city populations declining 10-20% in countries like France and the UK as suburbs absorbed 40-50% of metropolitan growth. Factors included economic recovery, rising incomes, and infrastructure like the UK's motorway system, but unlike the U.S., European suburbs often integrated multi-family units and public transit, limiting low-density sprawl. Globally, urbanization expanded rapidly in the , with the urban population proportion rising from approximately 16% in 1900 to 29% in 1950 and reaching 47% by 2000, shifting the epicenter from and —where 50-60% urbanization prevailed by mid-century—to developing regions like and , which accounted for 75% of new urban dwellers after 1950. This spread was propelled by industrialization, agricultural displacing rural labor, and migration to manufacturing hubs, though suburbanization in these areas often manifested as informal peri-urban settlements rather than planned U.S.-style tracts. In and , similar postwar booms mirrored Western patterns, with suburban populations doubling between 1950 and 1980 due to rail extensions and surges. By century's end, over 2.8 billion people lived in urban areas worldwide, marking a transition where developing countries' urbanization rates outpaced the developed world by factors of 2-3 annually in the and .

Drivers and Mechanisms

Economic Pull Factors

Economic pull factors represent the attractions of urban areas that draw individuals from rural regions primarily through prospects of higher earnings and opportunities. These factors stem from structural economic advantages in cities, including concentrated labor markets, diverse industries, and productivity enhancements via agglomeration economies, where firms and workers benefit from proximity through shared inputs, labor pooling, and knowledge spillovers. In historical contexts, such as the in and during the , mechanized factories offered wages substantially exceeding agricultural incomes, prompting mass rural-to-urban migration; for instance, urban manufacturing wages in Britain averaged 50-100% higher than rural farm labor by the mid-1800s. In contemporary developing economies, these pull factors manifest through rapid industrialization and service sector expansion, as seen in post-1980s reforms, where urban non-agricultural jobs provided multiples of rural , fueling urbanization rates that rose from 19% in 1980 to over 60% by 2020. Empirical data indicate persistent urban wage premiums, with dwellers globally earning approximately 33% more than rural counterparts due to these economic concentrations, though premiums vary by context—peaking at around 31% in the U.S. in 1940 before fluctuating with sectoral shifts. Agglomeration effects further amplify this by reducing transaction costs and fostering ; studies show that a 10% increase in correlates with 3-5% productivity gains across firms in developing countries. Urban centers also pull migrants via access to formal in and services, contrasting rural vulnerable to weather and market fluctuations. World Bank analyses of rural-urban migration in low-income nations highlight that expected urban income gains, often 2-3 times rural levels after accounting for migration costs, drive net flows, with over 50% of migrants citing job prospects as primary motivation in surveys from and . However, these benefits are not uniform; in advanced economies, the urban premium has narrowed for low-skilled workers amid , yet remains a key driver for skilled labor seeking specialized roles. Overall, economic pull factors underscore urbanization as a response to rational incentives for higher returns on labor, supported by evidence of sustained migration despite urban challenges.

Demographic and Migration Dynamics

Urban population growth arises from the interplay of demographic increase—births exceeding in urban areas—and net in-migration, with the latter dominating in most developing regions. According to estimates, rural-urban migration has historically accounted for a substantial portion of urbanization, particularly in and , where it contributes to over 50% of urban expansion in many countries when including territorial reclassifications. Globally, the urban reached 56% of the total in 2020, projected to rise to 68% by 2050, driven primarily by migration flows from rural hinterlands seeking economic opportunities. In developing countries, rural-urban migration is propelled by demographic pressures such as high rural rates and surpluses in agriculture, contrasted with urban pull factors including non-farm employment. World Bank analyses indicate that in low- and middle-income nations, this migration pattern has fueled rapid urban growth rates exceeding 3% annually in some regions during the late 20th and early 21st centuries. differentials exacerbate these dynamics: urban total rates (TFRs) are systematically lower than rural ones, often by 0.5 to 1.0 children per woman globally, reflecting factors like higher education, labor participation, and access to contraception in cities. This results in urban natural increase rates below replacement levels in many cases, making sustained in-migration essential to offset aging and low birth rates. International migration amplifies urban demographic shifts, as migrants tend to concentrate in gateway cities, contributing disproportionately to their . In high-income countries, immigrants comprise up to 20-30% of urban populations in major metros, bringing younger age structures and higher relative to native-born residents. This pattern underscores migration's role in countering urban declines, though it introduces challenges like integration and strains. In contrast, developed economies have witnessed counter-trends such as since the mid-20th century, where intra-metropolitan migration disperses populations outward, yet overall urbanization levels stabilize at high rates above 80%. These dynamics highlight migration's causal primacy in urbanization, independent of natural growth variations.

Technological and Infrastructure Enablers

The advent of key technological and infrastructural innovations in the 19th and 20th centuries overcame fundamental barriers to dense urban living, such as mobility limitations, disease risks from waste accumulation, energy constraints, and vertical space inefficiencies, thereby enabling unprecedented population concentrations in cities. These developments shifted urbanization from pre-industrial patterns constrained by walking distances to expansive, interconnected metropolitan systems supported by mechanized systems for transport, sanitation, power distribution, and high-rise construction. Transportation infrastructure played a central role by expanding access to labor markets and resources beyond immediate vicinities. Steam-powered railroads, emerging in the early , facilitated rural-to-urban migration and industrial agglomeration, with networks in and correlating to urban population surges as workers relocated for factory jobs. In the , automobiles and systems, particularly post-World War II, permitted decentralized urban forms and suburban expansion, as seen in North American cities where built-up areas grew faster than populations due to reduced travel costs. Sanitation and water supply systems addressed public health crises that previously capped urban densities. Mid-19th-century reforms, influenced by Edwin Chadwick's "sanitary idea" in England, emphasized engineered environments to combat epidemics like cholera, leading to widespread adoption of sewerage and waterworks that supported population booms by reducing mortality rates. In the United States, sanitary infrastructure expansions from the late 19th century onward handled surging urban demands, with systems designed explicitly for growth enabling cities to sustain millions without collapsing under waste-related diseases. The global sanitary revolution, involving piped water and sewers, similarly underpinned 19th- and 20th-century urban expansions by improving hygiene and habitability. Electrification provided reliable energy for lighting, machinery, and appliances, extending productive hours and supporting industrial clusters. Thomas Edison's in , operational from 1882, marked the first commercial central power plant, powering 85 buildings and laying groundwork for grid-based urban energy systems. By the , most American urban areas achieved near-universal access, transforming city functions with electric traction for streetcars and motors for factories, which in turn amplified agglomeration economies. Advances in building technology enabled vertical expansion on scarce land. Elisha Otis's safety elevator, demonstrated in 1853 with a fail-safe brake to prevent falls, made multi-story passenger transport feasible, directly contributing to skyscraper viability. Combined with steel-frame construction from the 1880s—exemplified by Chicago's (1885), the first true at 10 stories—these innovations reduced height-related costs and wind vulnerabilities, allowing densities that accommodated urban economic scaling. heights grew at 1.3% annually since 1900, driven by such efficiencies, fostering productivity gains through closer proximity in high-value locations.

Global Patterns and Variations

Regional Urbanization Rates

Urbanization rates vary widely by region, with advanced economies in and exhibiting high levels due to early industrialization, while developing regions like and show lower but rapidly increasing proportions driven by economic opportunities and pressures. As of 2020, recorded 82.7% of its in urban areas, followed closely by at 80.7%, reflecting decades of and urban-centric growth policies. stood at 74.8%, at 68.2%, at 50.5%, and at 43.0%, the lowest globally, underscoring persistent rural majorities in sub-Saharan contexts despite accelerating shifts. These disparities arise from differing paces of economic transformation and infrastructural capacity; for instance, Africa's low masks the world's fastest urban growth at over 3.5% annually in recent decades, fueled by natural increase and migration amid agricultural limitations. Projections indicate continued divergence in trajectories: by 2025, is expected to reach 83.9%, 83.0%, and 75.9%, with modest increments reflecting stabilized demographics, whereas Africa's rate could climb to 47.1% and Asia's to 53.7%, concentrating urban expansion in densely developing zones. Oceania's intermediate level at 69.5% projected for 2025 aligns with its island-based urban clusters.
RegionUrban Population (%) in 2020Projected Urban Population (%) in 2025
82.783.9
80.783.0
74.875.9
68.269.5
50.553.7
43.047.1
Data from World Urbanization Prospects 2018 Revision. Note that these figures rely on country-specific urban definitions, which introduce variability; the UN applies adjustments for comparability, though absolute thresholds differ (e.g., 2,000 inhabitants in some African nations versus density-based criteria elsewhere). Subregional nuances further highlight patterns, such as Eastern Asia's 64% urbanization contrasting Southern Asia's 36% in 2020, tied to varying industrialization histories and policy frameworks. In , Northern 's 53% exceeds sub-Saharan averages, attributable to earlier colonial urban legacies and resource economies. Overall, these rates underscore urbanization's uneven global footprint, with future increases hinging on efficacy in managing inflows without commensurate rural retention strategies.

Emergence of Megacities and Conurbations

Megacities, defined by the United Nations as urban agglomerations with populations exceeding 10 million inhabitants, first emerged in the mid-20th century. In 1950, only two such entities existed: New York with approximately 12.3 million residents and Tokyo with around 7 million, though Tokyo surpassed the threshold shortly thereafter. By 1975, the number had grown to five, primarily in developed regions, but accelerated urbanization in developing countries propelled the count to 10 by 1990 and 34 by 2023, with the majority now concentrated in Asia and Latin America. This proliferation reflects sustained rural-to-urban migration and natural population growth, outpacing infrastructure development in many cases. Conurbations, or extensive multi-city urban clusters formed through contiguous expansion and economic interdependence, represent an advanced stage of megacity evolution. The Tokyo-Yokohama , one of the earliest modern examples, integrated surrounding municipalities into a cohesive exceeding 37 million by the early 21st century, facilitated by post-World War II industrial recovery and networks. Similarly, Europe's Valley conurbation arose from 19th-century and industries, linking multiple cities into a 5-million-person industrial belt by the mid-20th century, though its growth has since stabilized. In the developing world, conurbations have expanded most dramatically since the 1980s due to export-oriented manufacturing and foreign investment. The in , encompassing , , and , transitioned from fragmented cities to the world's largest continuous urban area by 2015, surpassing with an estimated 42.6 million inhabitants across 7,000 square kilometers of built-up land, up from 4,500 square kilometers in 2000. This growth stemmed from special economic zones established in the late 1970s, attracting millions of migrants and fostering integrated supply chains. Other notable examples include the Yangtze River Delta around , with over 80 million in its extended agglomeration, and India's Mumbai-Pune corridor, where rapid infrastructure links have blurred city boundaries. These formations underscore how transportation advancements and policy-driven agglomeration enable conurbations to function as single economic units, amplifying productivity but straining resources. Projections indicate continued emergence, particularly in and , with potential new megacities like and reaching 20 million each by 2035, often evolving into amid limited planning. Empirical data from and analyses confirm that over 80% of recent megacity growth occurs in low- and middle-income countries, where conurbation formation correlates with GDP rises but also heightened vulnerability to and challenges.

Rural-Urban Migration Flows

Rural-urban migration constitutes the predominant mechanism fueling urban in developing regions, where natural increase alone insufficiently accounts for observed expansion rates. Between 2000 and 2019, high-resolution data indicate that migration accelerated urban growth in approximately 50% of the world's urban areas, contributing significantly to the global urban surpassing 4 billion by 2020. In and , internal migration flows from rural hinterlands to cities have driven the majority of urbanization, with 's urban share reaching about 50% and 's at 43% as of recent estimates. In , rural-to-urban migration has scaled massively, with 288 million migrants recorded in 2018, representing a workforce comparable to the entire of the at that time and underpinning the nation's urban transformation. This flow, often temporary or circular due to household registration systems, has sustained annual urban increases exceeding 20 million people in peak decades. India's rural-urban migration has similarly intensified, with urban dwellers comprising 37% of the (about 535 million) in 2024, up from prior decades, as economic opportunities draw laborers from agrarian regions despite infrastructure strains. Africa exhibits the fastest urbanization trajectory among continents, projected to see its urban population double by 2050, largely through rural exodus prompted by agricultural decline and urban job prospects. Intra-country movements predominate, with circular patterns common in East and West Africa, where migrants return seasonally for harvests. In Latin America, net rural-urban migration has stabilized post-1990s peaks but continues to shape conurbations, with balanced in- and out-flows in some nations per analyses. Globally, these flows exhibit spatiotemporal variation, with net migration rates ranging from near-zero to three per 1,000 people annually, concentrated in emerging economies where urban pull factors outweigh rural retention. While developed regions like and experienced net rural depopulation earlier, contemporary patterns in the Global South underscore migration's role in structural economic shifts, though barriers such as policy restrictions and climate shocks modulate volumes. Projections from the anticipate sustained inflows, elevating urban proportions to 68% worldwide by 2050, contingent on managed integration.

Economic Impacts

Productivity Gains and Innovation Hubs

Urban areas generate productivity gains through agglomeration economies, where the concentration of firms, workers, and reduces transaction costs, enables specialization, and facilitates matching between employers and employees. These effects manifest in thicker labor markets that allow for better allocation of , shared access to specialized inputs like suppliers and utilities, and localized learning from frequent interactions. Empirical studies consistently find that larger correlates with higher output per worker; for instance, a doubling of is associated with increases of 2-7 percent across various economies and city sizes. Cross-country data reveal a strong positive correlation between the share of urban population and GDP per capita, with urbanized nations averaging significantly higher incomes than rural-dominated ones, reflecting these efficiency advantages. Within countries, urban workers earn 20-50 percent more than rural counterparts on average, attributable to scale effects rather than just selection of higher-skilled individuals into cities. In developing economies, where baseline productivity is lower, agglomeration benefits can be even larger, though realization depends on complementary investments in transport and institutions to mitigate congestion. Cities also serve as innovation hubs by amplifying knowledge spillovers, where proximity accelerates the of ideas through formal channels like collaborations and informal ones like chance encounters. Metropolitan areas with high densities of educated workers exhibit elevated rates and R&D outputs , as evidenced by U.S. metro data showing that knowledge-intensive sectors thrive in environments with dense networks of inventors and firms. Global indices of innovation hubs, such as those ranking cities by agglomeration of talent and spillover effects, confirm that top performers like and derive sustained growth from these dynamics, outpacing less dense regions in technological advancement. However, these gains diminish beyond optimal scales if diseconomies like high costs erode net benefits, underscoring the need for policy to sustain urban without over-reliance on size alone.

Poverty Reduction and Income Convergence

Urbanization has been empirically linked to primarily through enhanced economic productivity and employment opportunities in urban areas, where GDP per capita correlates positively with higher urbanization rates across countries. In developing nations, rural-to-urban migration facilitates access to higher-wage jobs in , services, and , lifting migrants out of . For instance, between 1990 and 2019, global (under $1.90/day) declined from 36% to under 10%, coinciding with urbanization rates rising from 43% to 56%, with much of the reduction occurring as rural populations transitioned to urban economies. Evidence from underscores this dynamic: China's urbanization rate surged from 26% in 1990 to 64% by 2023, contributing to extreme poverty falling from 66% to near zero, as urban industrial clusters generated millions of jobs and remittances supported rural households. Similarly, in , urban poverty rates dropped from 10.7% to 1.1% between 2011-12 and 2022-23, narrower than rural declines but reflective of convergence as urban expansion absorbed rural migrants into formal . Studies confirm urbanization's spillover effects, including remittances and market linkages, reduce rural poverty by 0.5-1% per percentage point increase in urban proximity. Income convergence between urban and rural areas accelerates with urbanization, as urban land expansion narrows the gap by 0.005-0.011% per 1% increase in , driven by factor mobility and technology diffusion. However, aggregate urban headcounts can rise temporarily if migration exceeds job growth, as seen globally from 1993-2002 when urban poor increased by 50 million while rural poor fell by 150 million, yet overall absolute declined due to higher urban incomes. In , urbanization directly boosted rural household expenditures by improving non-farm employment access, evidencing causal poverty alleviation without relying on distorted policy narratives. This process aligns with causal mechanisms where fosters agglomeration economies, raising average incomes and enabling traps to break via scalable infrastructure and accumulation, though outcomes depend on to mitigate formation. Cross-country data from 163 nations (1991-2019) shows a 1% urbanization rise correlates with 0.168% fewer vulnerable instances, supporting convergence toward higher living standards. Despite biases in some academic sources overemphasizing urban challenges, empirical aggregates affirm urbanization's net role in global eradication.

Costs: Congestion, Housing Pressures, and Inequality

Urban congestion arises from the concentration of economic activity and population in limited spaces, leading to severe traffic delays and elevated transportation costs. In 2024, drivers in the world's 100 largest urban areas lost an average of 42 hours to congestion, with total global economic losses estimated at over $1 trillion annually, including wasted time, fuel, and productivity. In the United States, congestion cost drivers $771 per person in lost time value alone, equivalent to about one workweek, while freight trucking incurred $108.8 billion in delays in 2022 due to highway bottlenecks. These costs stem causally from rapid rural-urban migration overwhelming infrastructure capacity, as seen in cities like London and New York, where peak-hour delays exceed 50 hours per driver yearly. Housing pressures intensify with urbanization as demand surges from in-migrants outpace supply, constrained by land-use regulations, zoning laws, and construction barriers. Globally, over 1.6 billion people lack adequate housing, with urban affordability crises evident in median house-price-to-income ratios exceeding 9.0—deemed "severely unaffordable"—in markets like Hong Kong (16.7 in 2023) and Sydney (13.3). In the U.S., a shortage of 4.7 million homes as of 2025 has driven median home prices up 50% since 2019 in many metros, pricing out lower-income households and fueling informal settlements or homelessness in cities like Los Angeles and New York. This mismatch is exacerbated by urban containment policies that limit peripheral development, raising land costs and rents faster than wages; for instance, U.S. median rents rose 35% from pre-2020 levels amid urbanization-driven demand. Urbanization often amplifies income inequality, particularly in the initial phases of rapid growth, as low-skilled rural migrants enter high-productivity urban labor markets but face barriers like skill mismatches and informal . Empirical studies confirm an inverted-U relationship per Kuznets' , where inequality rises with early urbanization before potential long-term convergence; in , for example, urban expansion initially widened income gaps by 0.005-0.011% per 1% land increase due to uneven agglomeration benefits. Within cities, larger population densities correlate with higher racial, gender, and overall wage disparities, as skilled workers capture disproportionate gains from innovation hubs while migrants cluster in low-wage sectors. In developing economies like , urbanization has increased locality-level inequality by concentrating wealth in urban elites, though aggregate rural-urban gaps may narrow over decades. This dynamic reflects causal sorting of talent to , leaving behind rural areas and fostering urban underclasses, with city size directly predicting elevated Gini coefficients in cross-national data.

Social and Health Effects

Access Improvements: Education, Healthcare, and Social Mobility

Urbanization facilitates improved access to through the agglomeration of institutions, qualified educators, and learning resources in densely populated areas, enabling higher enrollment and completion rates compared to rural settings. A cross-regional in indicates that children growing up in urban areas consistently achieve higher levels of , including and , attributable to better school infrastructure and proximity to advanced institutions. Similarly, longitudinal from reveal that urban residency during childhood causally boosts adult earnings and employment probabilities by 5-10%, mediated in part by enhanced educational opportunities. In developing contexts, such as 11 Middle Eastern countries, a 1% rise in urbanization correlates with a 1.91% increase in access and up to 2.95% in tertiary access, particularly benefiting women through reduced geographic barriers. Healthcare access similarly benefits from urban concentration of hospitals, specialists, and infrastructure, resulting in lower exclusion rates and better preventive and curative services. Globally, 56% of rural residents lack essential health services, a figure more than double that in urban areas, due to sparse facilities and longer travel distances in countryside regions. assessments highlight that rural health systems suffer from weaker capacity and higher inequities in determinants like and coverage, whereas urban proximity to providers reduces mortality from treatable conditions; for example, urban-rural gaps in physician density reach 8.0 versus 5.1 per 10,000 residents in contexts like the , with analogous disparities worldwide. Empirical evidence from 175 countries further links urbanization to investments that elevate and reduce disease burdens, though localized can strain systems without adequate planning. These gains in and healthcare underpin social mobility by providing pathways to skill acquisition and health maintenance essential for labor market participation. Urban migration exposes individuals to diverse job networks and higher-wage sectors, with World Bank analyses showing urbanization as a key driver in —lifting over 1 billion people out of since 1990 through improved formation. Childhood urban exposure correlates with intergenerational income elasticity reductions, implying greater mobility; for instance, studies in varied economies demonstrate that urban-raised cohorts experience 10-15% higher absolute mobility rates via education-linked premiums. However, while access expands opportunities, realized mobility remains contingent on individual agency and policy environments, as urban settings can amplify volatility in low-income subgroups without supportive institutions. Overall, the causal chain from urban access to mobility reflects concentration's efficiency, outweighing rural isolation's constraints in aggregate empirical outcomes.

Challenges: Crime Rates, Mental Health, and Infectious Diseases

Urban areas consistently report higher rates than rural regions, with metropolitan statistical areas exhibiting approximately 300% more than rural areas, as documented in a analysis of U.S. data. This disparity arises from causal factors including population anonymity, which reduces informal social controls; greater opportunities for interpersonal conflict in dense settings; and the concentration of and inequality, which correlate with elevated rates in urban neighborhoods—often 3 to 4 times higher than citywide averages in high-poverty zones. Property s show more mixed patterns, with some studies indicating that urbanization may deter pecuniary offenses through increased and economic activity, though overall crime burdens remain heavier in cities due to volume and severity. Mental health challenges intensify in urban environments, where prevalence of common mental disorders such as depression and anxiety exceeds rural rates by modest but consistent margins—10.4% urban versus 8.9% rural in large-scale surveys of working-age populations. Meta-analyses of developed countries confirm urbanicity's association with higher depression prevalence, potentially driven by chronic stressors like , social disconnection amid superficial interactions, and disrupted circadian rhythms from artificial lighting and overcrowding. While rates are comparable overall, urban dwellers experience elevated symptoms of generalized anxiety (up to 6% higher severity) and functional impairments, compounded by limited access to spaces and community ties that buffer stress in rural settings. rates, conversely, skew higher rurally due to isolation and firearm availability, highlighting that urbanization trades acute social pressures for broader psychosocial strains.
High in cities facilitates the transmission of infectious diseases through elevated contact rates and interconnected mobility networks, as evidenced by historical outbreaks like the 19th-century epidemics in U.S. and European cities, where unsanitary crowding in tenements amplified waterborne spread, killing tens of thousands in places like in 1832. Modern examples include the 1918 , which surged in urban centers due to mass transit and workforce density, and SARS in 2003, originating in densely packed Asian markets before globalizing via air hubs. For , peer-reviewed analyses link to increased infection likelihood via direct proximity effects, though outcomes vary by socioeconomic controls like ventilation and ; initial waves hit cities harder, with structural equation models showing density's indirect role in elevating both cases and mortality through household overcrowding. While some studies question density's isolated impact amid confounding factors like inequality, causal realism underscores that urban proximity inherently raises basic reproductive numbers (R0) for respiratory pathogens, necessitating targeted interventions beyond .

Empirical Evidence on Net Health Outcomes

Empirical analyses of global panel data spanning 175 countries from 2000 to 2018 reveal that urbanization exerts a positive net effect on public health indicators, including reduced crude death rates and elevated life expectancy at birth. Specifically, a 1% rise in the urbanization rate correlates with a 0.494% decline in the crude death rate under instrumental variable estimation and a 0.179% increase in life expectancy using two-way fixed effects models, with effects amplified among women and in lower-income nations. These gains operate partly through economic channels, as urbanization elevates real GDP per capita by 0.573% per 1% increase, thereby funding health infrastructure and services. In high-income contexts like the , urban-rural disparities underscore this advantage: rural residents face systematically lower life expectancies, with a 60-year-old rural man projected to live approximately two years less than his urban counterpart, and similar gaps persisting across ages and genders due to inferior access to specialized care and preventive measures. Urban environments also exhibit lower mortality from chronic diseases compared to rural areas, reflecting denser networks of medical facilities and diagnostic capabilities that mitigate epidemiological burdens. Notwithstanding these benefits, urbanization introduces localized health costs, such as heightened exposure to and , which contribute to respiratory conditions and cardiovascular strain, alongside lifestyle shifts fostering and metabolic disorders. challenges, including elevated and stress from social density, further complicate outcomes, though empirical offsets via urban greening and service proximity often temper these. Systematic reviews of developing countries highlight mixed correlations—reductions in infectious disease prevalence through , juxtaposed with rises in non-communicable ailments—but aggregate mortality metrics consistently favor net improvements as urbanization facilitates the . Overall, serves as a robust proxy for net gains, with historical reversals of pre-modern urban penalties (high density-driven mortality) yielding contemporary advantages driven by and hubs; studies attributing predominant negatives often overlook confounders like convergence and selection effects in migrant flows. Cross-national robustness checks, including GMM and heteroscedasticity-based instruments, affirm toward positive net outcomes, particularly where enables efficient scaling of health systems.

Environmental Effects

Efficiency Benefits: Lower Per Capita Resource Use

Urban density enables in provision, reducing requirements for resources like , , and through shared systems such as , centralized , and compact spatial arrangements. This contrasts with dispersed rural patterns, where individual households or farms bear higher fixed costs for services like distribution and road maintenance, leading to elevated per-person usage. Empirical analyses confirm that higher densities correlate with diminished material and footprints, as proximity minimizes distances and facilitates efficient delivery networks. In terms of , urban areas typically exhibit lower consumption for transportation and residential purposes due to reliance on mass transit and multi-unit dwellings with shared walls that retain . A global econometric study across regions found that use declines with up to 4,000–22,000 persons per square kilometer, after which marginal gains plateau, attributing reductions to optimized building for heating and cooling. For instance, denser configurations result in smaller average dwelling sizes, cutting heating and cooling demands by up to 20–30% in scenarios projecting to 2050, as modeled in assessments of urban form impacts. Transportation is similarly reduced, with studies showing compact cities using 20–50% less fuel equivalent than sprawling suburbs or rural zones, driven by walking, , and public systems over private vehicles. Water resource efficiency follows analogous patterns, with urban piped networks and recycling technologies yielding lower per capita withdrawal rates compared to rural reliance on wells or surface sources prone to inefficiency. Data from integrated urban metabolism analyses indicate that cities achieve 10–25% reductions in per capita water use through metering and wastewater reuse, though this varies by governance; for example, Singapore's urban density supports a system recycling over 40% of used water, minimizing freshwater demands per resident. Land use per capita is starkly lower in urban settings, averaging 0.01–0.1 hectares per person versus 1–5 hectares in rural areas, as high-rise and mixed-use developments concentrate habitation and activity, preserving peripheral ecosystems from fragmentation. These efficiencies hold despite countervailing factors like higher commercial intensities in cities, with peer-reviewed models consistently demonstrating net savings when density exceeds rural baselines, underscoring urbanization's role in resource optimization absent policy distortions. However, realization depends on quality; poorly managed sprawl within urban peripheries can erode gains, as evidenced by elevated suburban energy profiles relative to cores.

Localized Drawbacks: Heat Islands, Pollution, and Habitat Loss

Urban areas exhibit the effect, where surface and air temperatures are elevated relative to surrounding rural landscapes due to heat retention by impervious surfaces like asphalt and , reduced from vegetation loss, and from human activities such as transportation and . Empirical measurements show average nighttime UHI intensities of 1–3°C in many cities, with peaks exceeding 7°C during heatwaves, as documented in global satellite data analyses. This localized warming amplifies energy demands for cooling, with a 0.5 K increase in UHI intensity linked to higher monthly building cooling loads in observational studies from European cities. In rapidly urbanizing lower-income regions, SUHI effects have intensified at rates up to twice those in wealthier areas since 2000, driven by unchecked construction and limited . Air pollution in urban locales stems from concentrated emissions of criteria pollutants like particulate matter (PM2.5 and PM10), nitrogen oxides, and volatile organic compounds, primarily from vehicular traffic, industrial operations, and residential heating, which are trapped by the urban canyon geometry of high-rises. In the United States, 2008–2012 data reveal mean annual PM2.5 concentrations of 11.15 μg/m³ in large central metropolitan counties, compared to 8.87 μg/m³ in nonmetropolitan rural counties, reflecting denser emission sources. Similar urban-rural gradients appear globally, with sulphate and primary PM2.5 levels consistently higher in cities due to localized combustion processes, though secondary pollutants like ozone may peak downwind. These concentrations contribute to acute respiratory issues and premature mortality, with urban exposure estimates indicating 10–20% higher health burdens than rural baselines in cohort studies. Habitat loss from urbanization involves the irreversible conversion of permeable natural or to impervious cover, fragmenting ecosystems and reducing available niches for . Although urban land occupies less than 3% of global terrestrial surface, it drives ≥5% of total loss for 26–39% of and plant species assessed in expansion models, particularly in hotspots like tropical regions. Projections indicate that by 2030, urban growth could cause 50% declines in local within affected sites, as impervious surfaces disrupt , , and trophic interactions. Fragmentation exacerbates this by isolating populations, increasing risks for edge-sensitive taxa, with empirical data from Neotropical cities showing direct correlations between built-up area expansion and avian and mammalian extirpations since the . via green corridors remains limited in scale, as prioritizes development over restoration in most cases.

Debunking Exaggerated Environmental Narratives

Urbanization is often portrayed in environmental advocacy as a primary driver of irreversible ecological collapse, with narratives emphasizing unchecked , skyrocketing global emissions, and on a planetary scale. These claims, frequently amplified by media and certain academic outlets, overlook causal mechanisms where dense urban forms enable in energy and resource use, leading to lower impacts compared to dispersed rural or suburban patterns. For instance, a 2023 analysis in Nature Cities found that declining urban population densities correlate with rising CO₂ emissions, as sprawl increases reliance on private vehicles and extends networks inefficiently. Empirical data consistently demonstrate that higher urbanization rates reduce carbon emissions through shared , compact heating/cooling systems, and reduced demands per person. A study of global trends from 1990 to 2020 revealed a negative relationship between urbanization rates and CO₂ emissions intensity, with each percentage point increase in urbanization linked to a 0.015% drop in emissions due to technological clustering and service efficiencies. In high-income countries, where urbanization exceeds 80%, further densification has been associated with emissions reductions, contrasting with narratives that equate city growth with proportional pollution spikes; for example, European cities like exhibit emissions 20-30% below national rural averages owing to modal shifts to and transit. This efficiency holds despite localized air quality challenges, as global models show urban areas accounting for just 70% of emissions while housing 55% of the world's , yielding a net sparing effect on total resource extraction. Exaggerations around deforestation and habitat loss similarly fail under scrutiny, as urbanization's land-sparing dynamics concentrate human activity, freeing marginal lands for reforestation or conservation—evident in the U.S., where forest cover rebounded from 30% in 1920 to over 33% by 2020 amid suburban-to-urban shifts. Claims of urban expansion as the dominant deforestation force ignore that commercial agriculture drives 80% of tropical losses, with urban footprints comprising under 3% of global land use yet supporting denser populations that curb per capita farmland needs by up to 50% through yield intensification. In Asia, rapid urbanization from 2000-2020 coincided with stabilized deforestation rates in urbanizing regions, as policy-induced cropland consolidation offset habitat pressures, challenging alarmist projections of inevitable "urban sprawl apocalypse." Such patterns underscore that while site-specific losses occur, aggregate environmental narratives inflate risks by disregarding adaptive human behaviors and technological offsets, including urban rewilding initiatives that have boosted city biodiversity metrics in places like Singapore by 20% since 2010. These debunkings highlight systemic overstatements in sources prone to advocacy-driven framing, where selective data on urban heat islands or amplify drawbacks without contextualizing net gains; rigorous econometric models, by contrast, affirm urbanization's role in decoupling economic growth from emissions, with projections indicating that sustained densification could cut global footprints by 10-15% by 2050 under current trends. Prioritizing over reveals urban forms not as villains but as pragmatic levers for , provided governance avoids subsidizing inefficient sprawl.

Policy and Planning Approaches

Organic Market-Driven Growth vs. Central Planning

Organic market-driven urban growth arises from decentralized decisions by property owners, developers, and residents, guided by price signals, property rights, and voluntary exchanges rather than comprehensive government blueprints. This approach enables cities to adapt dynamically to population influxes and economic shifts, fostering housing supply responsiveness through entrepreneurial experimentation. In , , the absence of traditional Euclidean since its founding has allowed flexible , permitting mixed developments and infill that accommodate demand without predefined restrictions. Empirical analyses indicate that such minimal regulation correlates with higher housing supply elasticity; for instance, Houston's regulatory environment has sustained median single-family home prices below $350,000 as of 2023, enabling broader access amid rapid from 2.1 million in 2000 to over 2.3 million in 2020. In contrast, central planning imposes top-down directives, such as urban growth boundaries (UGBs), comprehensive codes, or master plans, aiming to control density, infrastructure, and aesthetics through state authority. Proponents argue it prevents sprawl and coordinates services, yet evidence reveals frequent misallocations due to planners' limited foresight into local needs and market feedbacks. Portland, Oregon's UGB, implemented in 1973 and expanded selectively, has constrained peripheral development, contributing to housing price escalations; by 2023, median home prices exceeded $500,000, over 40% higher than Houston's after adjusting for income, with supply shortages exacerbating affordability crises during demand surges. , Brazil's purpose-built capital inaugurated in 1960 under a rigid modernist plan by and , exemplifies planning's pitfalls: its superblock design prioritized monumental axes over organic neighborhoods, resulting in automobile dependency, social segregation, and unplanned peripheral sprawl that housed 70% of residents outside the core by 2015, undermining intended equity and efficiency. Comparative studies underscore market-driven models' superior outcomes in affordability and adaptability. Cities with lax land-use controls, like , exhibit lower housing costs and reduced rates—Houston's rate stood at 10.8 per 10,000 in 2022 versus Portland's 18.7—attributable to permissive subdivision rules allowing smaller lots and denser builds where viable. Central planning often amplifies inequalities by favoring elite visions over incremental, bottom-up evolution; historical cases in centrally planned economies, such as Soviet-era cities, demonstrated resource misallocation and , with abatement deferred due to growth priorities that ignored market incentives. While planning can yield coordinated infrastructure in theory, empirical deviations—evident in Brasília's persistent and fiscal strains—highlight how ignoring dispersed leads to rigid structures ill-suited to human-scale interactions and economic variability. Thus, promotes resilient urban forms by harnessing self-organizing market processes, whereas central planning risks and unintended scarcities.

Case Studies of Policy Successes and Failures

Houston's absence of traditional ordinances, rejected by voters in referenda in , , and 1993, has facilitated rapid urban expansion and relatively compared to zoned peer cities. By 2023, median home prices in stood at approximately $320,000, significantly lower than in ($1.3 million) or New York ($700,000), enabling higher rates of homeownership and adaptation to population inflows through market-driven land use, such as deed restrictions and subdivision regulations rather than rigid Euclidean . This approach has supported , with the metro area adding over 1 million residents between 2010 and 2020 while maintaining per capita housing costs below national averages, though it has also contributed to low-density sprawl and infrastructure strains. In , , a master plan adopted in 1966 emphasized integrated land-use and transportation policies, including the pioneering (BRT) system launched in the 1970s, which by 2010 carried over 2 million passengers daily and reduced private vehicle use by promoting linear development along transit corridors. Empirical assessments indicate the city's sustainable urban mobility index reached 0.747 globally in benchmarking studies, reflecting efficiencies in coverage, (over 100 km of bike paths by 2020), and green spaces (52 square meters per inhabitant), which correlated with lower congestion and emissions compared to unplanned peers like . These policies, enforced through exclusionary zoning for high-density nodes, fostered economic vitality, with GDP per capita rising 4% annually in the 2000s, though peripheral inequalities persist. Conversely, the Pruitt-Igoe public housing complex in , constructed between 1954 and 1957 under federal , exemplified failures in top-down modernist design and social engineering, housing 2,870 families in 33 eleven-story slabs but descending into crime and abandonment by the late 1960s due to inadequate maintenance, skipped "skip-stop" elevators fostering isolation, and concentration of without community integration. Vacancy rates exceeded 70% by 1972, leading to its demolition starting that year, at a total cost exceeding $36 million (equivalent to $250 million today), highlighting flaws in assuming architectural could override socioeconomic incentives and local deficits. Brasília, Brazil's planned capital inaugurated in 1960, represented a utopian failure of centralized under President , with its airplane-shaped layout by prioritizing monumental axes and superblocks over organic neighborhoods, resulting in automobile dependency (over 90% of trips by car initially) and social segregation as low-income workers were relegated to distant satellite towns lacking services. Despite housing 3 million residents by 2020, the city's rigid functional zoning failed to generate vibrant public spaces, with empirical studies showing higher per capita travel distances and isolation compared to unplanned Brazilian cities, underscoring the pitfalls of imposing elite visions without market feedback or incremental adaptation. China's state-directed urbanization since the 2000s produced numerous "ghost cities," such as Ordos in and parts of Zhengdong New District, where overinvestment in —totaling trillions of yuan in unused high-rises and roads by 2015—stemmed from incentives to meet GDP targets via land sales rather than demand signals. At least 28 such underoccupied developments across 16 provinces wasted resources, with occupancy rates below 50% in many cases as late as 2020, exacerbating ( owed $9 trillion by 2023) and inefficient , as central planning decoupled supply from actual migration patterns and household preferences. While some areas later filled amid broader urbanization (rural-to-urban migration reaching 60% by 2023), the initial overbuild illustrates causal risks of politicized quotas over empirical needs assessment.

Contemporary Debates: Density Policies and Zoning Reforms

Density policies in urban areas have sparked intense debate, particularly regarding zoning reforms aimed at increasing housing supply through upzoning and reduced restrictions on multi-family development. Advocates, often aligned with the "YIMBY" movement, contend that exclusionary zoning—prevalent in many U.S. cities since the mid-20th century—artificially limits supply, driving up prices and exacerbating homelessness. They argue that permitting higher densities, such as triplexes or small apartment buildings in formerly single-family zones, would align development with demand, lowering per-unit costs via economies of scale in construction. Empirical analyses support modest supply gains from such reforms; a review of 180 U.S. zoning changes found an average 0.8% increase in housing stock three to nine years post-reform, with stronger effects from density-allowing policies. Critics, including neighborhood preservation groups, highlight potential downsides, asserting that densification without upgrades leads to congestion, strained utilities, and reduced livability. High-density policies can elevate volumes, contributing to 14-34% of congestion costs via impacts like exposure, even as overall may curb per-capita vehicle miles traveled. Studies indicate mixed quality-of-life outcomes: while density facilitates transit access and potentially lowers depression risks through , it correlates with higher , heat, and accident rates in under-planned areas. These concerns fuel "" resistance, prioritizing local character and service capacity over aggregate supply gains, though evidence suggests opposition often stems from fears of property value shifts rather than purely empirical limits. The 2040 Plan exemplifies reform efforts, eliminating citywide in 2019 to allow three units per lot by right. By 2024, housing permits rose 36% relative to pre-reform trends, and synthetic control analyses estimate 2-3% slower annual home price growth compared to similar cities, alongside moderated rent increases. This contrasts with California's Senate Bill 9 (), which permits lot splits into duplexes on single-family parcels; despite ending exclusive statewide, applications totaled under 1,000 in the first two years, hampered by mandates, high subdivision costs, and local resistance, yielding negligible supply impacts. Broader critiques question efficacy amid persistent demand pressures; even successful upzoning in one spills over to adjacent areas without regional coordination, diluting local benefits. lags remain a flashpoint: densification boosts energy efficiency and resource use but risks overload on roads and sewers absent parallel investments, as seen in global models projecting heightened urban vulnerabilities. Pro-density studies, often from policy-oriented institutes, may underemphasize these fiscal burdens due to institutional preferences for compact growth, while market-driven evidence underscores that supply elasticities vary by land costs and regulations. Ongoing debates thus pivot toward hybrid approaches, blending with mandates for concurrent funding to balance affordability gains against localized strains.

Developments in the 2020s: Resilience and Digital Integration

The from 2020 onward exposed vulnerabilities in urban systems but also accelerated adaptations enhancing resilience, particularly in cities with pre-existing diversified and responsive . Empirical analyses of global urban responses indicated that decentralized, mixed-use layouts with short commutes reduced transmission risks and supported faster economic rebounds compared to sprawling or overly centralized models. For example, transit-oriented neighborhoods in demonstrated superior recovery trajectories post-2022 lockdowns, with subway-adjacent areas regaining pre-pandemic activity levels 15-20% faster than peripheral zones due to integrated resilience. By 2023, over 68% of surveyed cities worldwide had revised priorities to prioritize shock absorption, including diversified supply chains and to mitigate cascading failures from health or climate events. Urban resilience frameworks evolved in the mid-2020s to incorporate multi-hazard , drawing lessons from disruptions to inform climate and economic strategies. The OECD's four-pronged approach—emphasizing cross-policy collaboration, data-driven , adaptive , and inclusive —gained traction, with cities like those in the Resilient Cities Network allocating budgets for resilience finance, such as blended public-private investments totaling billions by 2025 to buffer against downturns. Peer-reviewed studies post-2020 underscored that cities investing in redundant systems, like backup power grids and modular , achieved 25-30% lower downtime during secondary shocks, such as 2023-2024 floods in and . This shift reflected causal links between proactive and reduced long-term costs, countering narratives of inevitable urban fragility by prioritizing empirical metrics over alarmist projections. Digital integration emerged as a core enhancer of in the 2020s, with technologies like AI, IoT, and digital twins enabling real-time monitoring and . Post-2020, cities with advanced digital infrastructures, including widespread and sensor networks, reported 20-40% faster recovery from disruptions, as platforms optimized resource allocation during lockdowns and supply shortages. For instance, empirical from Chinese cities showed that higher indices—measured by broadband penetration and adoption—correlated with GDP rebounds exceeding national averages by up to 5% in 2021-2022, attributing causality to streamlined remote services and virtual supply chains. By 2025, trends included urban digital twins for simulating resilience scenarios, with over 100 major cities deploying them to model responses or flows, integrating AI for autonomous mobility and optimization. These tools, while promising efficiency gains, highlighted trade-offs like risks and digital divides exacerbating inequalities in less-connected areas.

Projections to 2050: Asia-Pacific Dominance and Housing Crises

By 2050, the global urban population is projected to reach 6.68 billion, comprising 68 percent of the world's total population, with Asia and the Pacific region accounting for over 50 percent of this growth due to sustained rural-to-urban migration and natural population increases. In Asia alone, countries like India and China are expected to add 416 million and 255 million urban dwellers, respectively, dwarfing contributions from other regions and solidifying the Asia-Pacific's dominance in urban expansion. This trajectory reflects underlying economic pulls, including job opportunities in manufacturing and services, though it strains infrastructure in densely populated areas. The is forecasted to host two-thirds of the world's megacities—defined as urban agglomerations exceeding 10 million residents—rising from 17 such cities currently to a share among the projected 67 globally by 2050. Urban population in the region is anticipated to swell to 3.2 billion, a 50 percent increase from current levels, driven by rapid industrialization in nations like and alongside China's ongoing internal migrations. These projections underscore a shift toward mid-sized cities (1-5 million residents) absorbing much of the influx, potentially alleviating pressure on existing megacities but requiring scaled-up planning to manage density. Parallel to this dominance, acute housing crises are expected to intensify across urban centers, where supply lags behind demand due to regulatory hurdles, land scarcity, and speculative practices. By 2050, the region will require at least 40 million additional units to accommodate new urbanites, yet affordability gaps persist, with low-income migrants often relegated to informal settlements amid stagnant wages and insufficient public investment. In and , for instance, urban shortages could affect hundreds of millions, exacerbated by restrictions that limit construction and favor high-end developments over mass-market options. from current trends indicates that without deregulation and market-oriented policies, populations may expand, undermining productivity gains from urbanization.

Adaptation Strategies for Sustainability and Growth

Cities employ (NbS), such as urban green spaces, permeable pavements, and green roofs, to mitigate climate risks like heat islands and flooding while supporting through multifunctional . Empirical analyses indicate that NbS in natural or semi-natural settings reduce urban temperatures by up to 5°C and enhance stormwater management, yielding more synergies than trade-offs compared to engineered alternatives. These approaches prove cost-effective, with implementation costs often 50% lower than gray infrastructure for equivalent flood protection, allowing resources to be redirected toward . Urban planning policies emphasizing compact development and transit-oriented designs curb sprawl-induced emissions, limiting projected global urban growth to 540 exajoules by 2050 under optimized scenarios. By prioritizing mixed-use zoning and efficient networks, these strategies decrease vehicle kilometers traveled by 20-30% in high-density implementations, preserving and reducing without constraining GDP gains tied to agglomeration economies. Mainstreaming such into general frameworks outperforms isolated policies, as integrated approaches align development with resilience, evidenced by lower indices in cities like those in Europe's adaptation assessments. Digital integration, including IoT sensors for real-time resource monitoring and , enables of water, , and systems, fostering circular economies that recycle up to 70% of urban waste into energy or materials. Case studies from 2020s implementations, such as scalable NbS in flood-prone areas, demonstrate reduced economic losses from by 15-25% while accommodating growth through data-driven zoning adjustments. These evidence-based tactics prioritize causal mechanisms like reduced impervious surfaces for natural restoration, countering biases in overly alarmist narratives by focusing on verifiable, scalable outcomes over unproven mandates.

References

  1. https://ourworldindata.org/urbanization
  2. https://www.worldbank.org/en/topic/urbandevelopment/overview
  3. http://article.sapub.org/10.5923.j.env.20180802.03.html
  4. https://www.nber.org/system/files/working_papers/w19745/w19745.pdf
  5. https://publichealthreviews.biomedcentral.com/articles/10.1186/s40985-019-0116-0
  6. https://www.un.org/uk/desa/68-world-population-projected-live-urban-areas-2050-says-un
  7. https://www.epa.gov/caddis/urbanization-overview
  8. https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2664.13358
  9. https://onlinelibrary.wiley.com/doi/10.1002/9781119429333.ch16
  10. https://archive.nptel.ac.in/content/storage2/courses/109104047/lecture1/1_5.htm
  11. https://www.etymonline.com/word/urbanization
  12. https://www.oed.com/dictionary/urbanization_n
  13. https://databank.worldbank.org/metadataglossary/world-development-indicators/series/SP.URB.TOTL.IN.ZS
  14. https://population.un.org/wup/faqs
  15. https://blogs.worldbank.org/en/sustainablecities/how-do-we-define-cities-towns-and-rural-areas
  16. https://unhabitat.org/sites/default/files/2020/06/city_definition_what_is_a_city.pdf
  17. https://www.census.gov/newsroom/blogs/random-samplings/2022/12/redefining-urban-areas-following-2020-census.html
  18. https://ourworldindata.org/grapher/population-threshold-for-urban-area
  19. https://databank.worldbank.org/metadataglossary/world-development-indicators/series/SP.URB.TOTL
  20. https://penniur.upenn.edu/publications/un-endorses-a-uniform-measure-for-urbanization
  21. https://unstats.un.org/unsd/statcom/51st-session/documents/BG-Item3j-Recommendation-E.pdf
  22. https://www.sciencedirect.com/science/article/pii/S0094119020300838
  23. https://human-settlement.emergency.copernicus.eu/degurbaOverview.php
  24. https://journals.sagepub.com/doi/10.1177/0160017612449981
  25. https://pmc.ncbi.nlm.nih.gov/articles/PMC2001275/
  26. https://www.sciencedirect.com/science/article/pii/S0305750X22001310
  27. https://www.sciencedirect.com/science/article/pii/S2589004224013506
  28. https://www.journals.uchicago.edu/doi/10.1086/725907
  29. https://web.ics.purdue.edu/~rauhn/CWC_text/CWC_4.htm
  30. https://courses.lumenlearning.com/suny-hccc-worldcivilization/chapter/cities-of-the-indus-valley-civilization/
  31. http://www.unm.edu/~gbawden/328-egurb/328-egurb.htm
  32. https://escholarship.org/uc/item/9df4w6kn
  33. https://www.cambridge.org/core/books/violence-kinship-and-the-early-chinese-state/central-plains-civilization-from-erlitou-to-anyang/E11DDB2BB7F4A961998D8F5F920EEEB7
  34. https://par.nsf.gov/servlets/purl/10198052
  35. https://irows.ucr.edu/research/citemp/estcit/estcit.htm
  36. https://www.nber.org/system/files/working_papers/w28597/w28597.pdf
  37. https://pmc.ncbi.nlm.nih.gov/articles/PMC7186836/
  38. https://www.nber.org/digest/202204/enclosure-rural-england-boosted-productivity-and-inequality
  39. https://sites.udel.edu/britlitwiki/the-enclosure-acts/
  40. https://www.sciencedirect.com/science/article/abs/pii/S0921800902000290
  41. https://www.campop.geog.cam.ac.uk/blog/2024/10/17/industrial-manchester/
  42. https://sites.socsci.uci.edu/~dbogart/Marketaccessgrowth_presteam_jan102020.pdf
  43. https://courses.lumenlearning.com/suny-ushistory2ay/chapter/the-rise-of-suburbs-2/
  44. https://www2.umbc.edu/che/tahlessons/pdf/Post-War_Suburbanization_Homogenization%28PrinterFriendly%29.pdf
  45. https://reason.org/commentary/examining-sprawl-in-europe-and/
  46. https://digitalcommons.tourolaw.edu/context/scholarlyworks/article/1426/viewcontent/sprawl_in_europe___lewyn.pdf
  47. https://population.un.org/wup/assets/WUP2018-Report.pdf
  48. https://research.upjohn.org/cgi/viewcontent.cgi?article=1256&context=reports
  49. https://www.sciencedirect.com/science/article/pii/S2405844023109807
  50. http://www.diva-portal.org/smash/get/diva2:1670231/FULLTEXT01.pdf
  51. https://oxfordre.com/economics/display/10.1093/acrefore/9780190625979.001.0001/acrefore-9780190625979-e-153
  52. https://motu.nz/assets/Documents/our-work/urban-and-regional/auckland-issues/Cities-and-Skills.pdf
  53. https://www.nber.org/system/files/working_papers/w31387/w31387.pdf
  54. https://openknowledge.worldbank.org/entities/publication/f264e3b0-5fb5-52d9-a6ec-4bffa3bbdde5
  55. https://openknowledge.worldbank.org/bitstreams/4381bf0a-56fa-5c1a-a15d-7a3df43ae227/download
  56. https://www.sciencedirect.com/science/article/abs/pii/S0166046221000739
  57. https://www.nber.org/papers/w31387
  58. https://regions.regionalstudies.org/ezine/article/urbanization-cities-and-economic-growth-trends-recent-evidence-and-policy-implications/?print=print
  59. https://population.un.org/wup/
  60. https://www.migrationdataportal.org/themes/urbanisierung-und-migration
  61. https://openknowledge.worldbank.org/entities/publication/157dad4f-9cbf-54aa-94d3-9c688c0876ab
  62. https://documents1.worldbank.org/curated/en/260581617988607640/pdf/Demographic-Trends-and-Urbanization.pdf
  63. https://pure.iiasa.ac.at/id/eprint/18729/1/WP-23-004.pdf
  64. https://ourworldindata.org/global-decline-fertility-rate
  65. https://www.un.org/development/desa/pd/sites/www.un.org.development.desa.pd/files/undesa_pd_2025_wfr_2024_final.pdf
  66. https://www.frbsf.org/research-and-insights/publications/economic-letter/2023/07/why-immigration-is-an-urban-phenomenon/
  67. https://www.weforum.org/stories/2017/10/how-migration-is-changing-world-cities-charts/
  68. https://documents.worldbank.org/en/publication/documents-reports/documentdetail/260581617988607640/demographic-trends-and-urbanization
  69. https://naturesacred.org/brief-history-urban-infrastructure/
  70. https://transportgeography.org/contents/chapter8/transportation-urban-form/
  71. https://ajph.aphapublications.org/doi/10.2105/AJPH.91.12.1944
  72. https://onlinelibrary.wiley.com/doi/10.1111/joes.12607
  73. https://americanhistory.si.edu/explore/stories/power-people-rural-electrification-brought-more-lights
  74. https://www.6sqft.com/elisha-otis-now-162-year-old-invention-made-skyscrapers-practical/
  75. https://personal.lse.ac.uk/ahlfeldg/WP/GA_JB_-_Skyskrapers.pdf
  76. https://population.un.org/wup/DefinitionOfUrban/
  77. https://www.prb.org/international/indicator/urban/map/subregion/
  78. https://wilo.com/en/Pioneering/Stories/Understanding-Megacities-Dynamics-and-Realities-of-Urban-Centers-Worldwide_40512.html
  79. https://education.nationalgeographic.org/resource/history-cities/
  80. https://www.sciencedirect.com/science/article/abs/pii/S0305750X17301614
  81. https://www.sciencedirect.com/science/article/pii/S0034425719303724
  82. https://earthobservatory.nasa.gov/images/86603/the-worlds-largest-urban-area
  83. https://eros.usgs.gov/earthshots/pearl-river-delta-china
  84. https://www.oxfordeconomics.com/resource/rise-of-new-megacities-will-drive-global-urban-growth/
  85. https://www.statista.com/topics/4841/megacities/
  86. https://www.visionofhumanity.org/the-rise-of-megacities-and-urban-migration/
  87. https://www.nature.com/articles/s41562-023-01689-4
  88. https://www.ccpr.ucla.edu/wp-content/uploads/2022/06/Chen-Zhenxiang-1.pdf
  89. https://www.orfonline.org/expert-speak/the-state-of-cities-comparing-india-and-china-s-urban-trajectories
  90. https://www.iom.int/resources/urban-migration-trends-challenges-and-opportunities-india
  91. https://www.un.org/development/desa/dspd/wp-content/uploads/sites/22/2022/09/Pragna-Rugunanan-Migration-and-Urbanization-Trends-in-Africa.pdf
  92. https://africacenter.org/spotlight/african-migration-trends-to-watch-in-2024/
  93. https://popcouncil.org/insight/the-potential-of-internal-migration-to-shape-rural-and-urban-populations-across-africa-asia-and-latin-america/
  94. https://pmc.ncbi.nlm.nih.gov/articles/PMC10663150/
  95. https://www.sciencedirect.com/science/article/abs/pii/B9780444595171000052
  96. https://cep.lse.ac.uk/pubs/download/sercdp0027.pdf
  97. https://ourworldindata.org/grapher/urbanization-vs-gdp
  98. https://www.oecd.org/content/dam/oecd/en/publications/reports/2013/03/urban-to-rural-population-growth-linkages_g17a2268/5k49lcrq88g7-en.pdf
  99. https://www.bls.gov/opub/mlr/2015/beyond-bls/how-knowledge-spillover-contributes-to-economic-growth-in-metro-areas.htm
  100. https://hceconomics.uchicago.edu/sites/default/files/pdf/events/Rosenthal_Strange_2004_HbRegUrbEcon_evidence-nature-sources.pdf
  101. https://www.nature.com/articles/d42473-022-00486-3
  102. https://www.sciencedirect.com/science/article/pii/S175778022400009X
  103. https://ourworldindata.org/poverty
  104. https://data.worldbank.org/indicator/SP.URB.TOTL.IN.ZS
  105. https://data.worldbank.org/indicator/SP.URB.TOTL.IN.ZS?locations=CN
  106. https://www.facebook.com/etnow/posts/the-world-bank-highlighted-that-between-2011-12-and-2022-23-india-reduced-extrem/1089024959923074/
  107. https://www.tandfonline.com/doi/full/10.1080/1331677X.2023.2167730
  108. https://www.sciencedirect.com/science/article/pii/S0264275122002700
  109. https://openknowledge.worldbank.org/entities/publication/ce274b96-19e2-5b6a-9f05-4091bae6d6e5
  110. https://shs.hal.science/halshs-03541680/document
  111. https://documents.worldbank.org/curated/en/743171468151775418/pdf/766680JRN0WBRO00Box374385B00PUBLIC0.pdf
  112. https://www.sciencedirect.com/science/article/abs/pii/S0264275123000203
  113. https://documents1.worldbank.org/curated/en/371511468314708097/pdf/wps419901update1.pdf
  114. https://inrix.com/scorecard/
  115. https://siteselection.com/congestion-capitals/
  116. https://www.ccjdigital.com/business/article/15711348/americans-waste-a-week-annually-in-traffic-congestion-report-says
  117. https://www.migrationpolicy.org/article/housing-crisis-immigrants-integration
  118. https://www.chapman.edu/communication/_files/Demographia-International-Housing-Affordability-2025-Edition.pdf
  119. https://www.uschamber.com/economy/the-state-of-housing-in-america
  120. https://home.treasury.gov/news/featured-stories/rent-house-prices-and-demographics
  121. https://constructioncoverage.com/research/cities-with-the-largest-rent-increases-decreases
  122. https://hpe-rpe.org/ief/239/248-1-2024/5393/the-welfare-inequality-and-growth-effects-of-urbanization-empirical-evidence-from-china-2.pdf
  123. https://www.tandfonline.com/doi/full/10.1080/07352166.2023.2252538
  124. https://so05.tci-thaijo.org/index.php/TER/article/view/263701
  125. https://www.frontiersin.org/journals/environmental-science/articles/10.3389/fenvs.2022.1065941/full
  126. https://academic.oup.com/joeg/article/21/5/683/5998980
  127. https://uu.diva-portal.org/smash/get/diva2:1699279/FULLTEXT01.pdf
  128. https://www.researchgate.net/publication/336724677_Urbanization_and_Women%27s_Access_to_Tertiary_Education_Case_of_11_Middle_East_Countries
  129. https://www.ilo.org/resource/news/more-half-global-rural-population-excluded-health-care
  130. https://www.who.int/activities/addressing-health-inequities-among-people-living-in-rural-and-remote-areas
  131. http://www.ers.usda.gov/data-products/charts-of-note/chart-detail?chartId=106208
  132. https://pmc.ncbi.nlm.nih.gov/articles/PMC9852986/
  133. https://www.voanews.com/a/urbanization-curbs-poverty-says-world-bank/1648092.html
  134. https://www.sciencedirect.com/science/article/abs/pii/S0305750X20301273
  135. https://www.nber.org/system/files/working_papers/w5430/w5430.pdf
  136. https://www.brookings.edu/articles/the-path-to-public-safety-requires-economic-opportunity/
  137. https://www.sciencedirect.com/science/article/pii/S009411902500052X
  138. https://ophrp.org/journal/view.php?doi=10.24171/j.phrp.2023.0385
  139. https://www.sciencedirect.com/science/article/abs/pii/S0165032723010066
  140. https://pmc.ncbi.nlm.nih.gov/articles/PMC10553337/
  141. https://pmc.ncbi.nlm.nih.gov/articles/PMC7119955/
  142. https://news.northeastern.edu/2019/08/08/six-epidemics-from-american-history-show-how-urban-design-affects-our-health/
  143. https://pmc.ncbi.nlm.nih.gov/articles/PMC7123574/
  144. https://www.sciencedirect.com/science/article/pii/S0264275123003311
  145. https://www.tandfonline.com/doi/full/10.1080/01944363.2020.1777891
  146. https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2022.1096964/full
  147. https://pmc.ncbi.nlm.nih.gov/articles/PMC11402582/
  148. https://www.pbs.org/newshour/health/new-research-finds-rural-americans-dont-live-as-long-as-city-dwellers
  149. https://pmc.ncbi.nlm.nih.gov/articles/PMC10126956/
  150. https://www.nature.com/articles/s41598-024-76813-z
  151. https://bmcpublichealth.biomedcentral.com/articles/10.1186/1471-2458-13-513
  152. https://www.sciencedirect.com/science/article/pii/S240584402402913X
  153. https://pmc.ncbi.nlm.nih.gov/articles/PMC10002195/
  154. https://pmc.ncbi.nlm.nih.gov/articles/PMC10937705/
  155. https://lcluc.umd.edu/sites/default/files/lcluc_documents/Global%2520scenarios%2520of%2520urban%2520density%2520and%2520its%2520impacts%2520on%2520building%2520energy%2520use%2520through%25202050.pdf
  156. https://energy.sustainability-directory.com/question/how-does-urban-density-affect-energy-use/
  157. https://www.sciencedirect.com/science/article/abs/pii/S0140988322000743
  158. https://journal-buildingscities.org/articles/10.5334/bc.72
  159. https://www.sciencedirect.com/science/article/pii/S2405844024033498
  160. https://www.treehugger.com/urban-or-rural-which-is-more-energy-efficient-4863586
  161. https://www.epa.gov/heatislands/what-are-heat-islands
  162. https://www.sciencedirect.com/science/article/pii/S095937802100220X
  163. https://pmc.ncbi.nlm.nih.gov/articles/PMC8169988/
  164. https://www.nature.com/articles/s42949-025-00198-9
  165. https://ehjournal.biomedcentral.com/articles/10.1186/s12940-017-0314-5
  166. https://www.cdc.gov/mmwr/volumes/66/ss/ss6613a1.htm
  167. https://www.nature.com/articles/s41598-020-74524-9
  168. https://research.fs.usda.gov/treesearch/download/52798.pdf
  169. https://www.pnas.org/doi/10.1073/pnas.2117297119
  170. https://www.nature.com/articles/s41467-022-29324-2
  171. https://www.sciencedirect.com/science/article/abs/pii/S0006320721001166
  172. https://www.centreforcities.org/blog/cities-are-bad-for-the-environment-myth-debunked/
  173. https://www.nature.com/articles/s42949-023-00084-2
  174. https://ideas.repec.org/a/eee/enepol/v151y2021ics0301421521000409.html
  175. https://www.mdpi.com/2071-1050/16/18/7878
  176. https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2022.848800/full
  177. https://news.climate.columbia.edu/2010/02/11/urbanization-deforestation-reforestation/
  178. https://www.usgs.gov/index.php/programs/climate-adaptation-science-centers/news/sparing-or-sharing-effects-urbanization
  179. https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2664.12908
  180. https://www.sciencedirect.com/science/article/abs/pii/S0048969719354701
  181. https://www.mdpi.com/2071-1050/15/6/5116
  182. https://www.mercatus.org/research/policy-briefs/link-between-local-zoning-policy-and-housing-affordability-americas-cities
  183. https://kinder.rice.edu/urbanedge/houston-without-zoning-arbitrary-lines
  184. https://www.cato.org/briefing-paper/housing-markets-first-housing-supply-affordability-are-key-reducing-homelessness
  185. https://www.sciencedirect.com/science/article/abs/pii/S0264275109001176
  186. https://www.aeaweb.org/conference/2020/preliminary/paper/bFHQK9D8
  187. https://cayimby.org/blog/more-housing-options-lower-prices-evidence-from-houston-portland-and-auckland/
  188. https://www.mdpi.com/2071-1050/11/2/553
  189. https://archive.curbed.com/2019/6/7/18657121/brasilia-brazil-urban-planning-architecture-design
  190. https://www.tandfonline.com/doi/pdf/10.1080/08941929409380854
  191. https://reason.org/commentary/houstons-housing-success-a-model-for-cities/
  192. https://manhattan.institute/article/houstons-no-zone-recipe-keeps-housing-prices-in-check
  193. https://www.asce.org/publications-and-news/civil-engineering-source/civil-engineering-magazine/issues/magazine-issue/article/2025/07/brazils-curitiba-has-been-following-its-master-plan-for-60-years
  194. https://www.sciencedirect.com/science/article/abs/pii/S0967070X12000558
  195. https://www.researchgate.net/publication/268002125_A_case_study_of_sustainable_urban_planning_principles_in_Curitiba_Brazil_and_their_applicability_in_Shiraz_Iran
  196. https://fee.org/articles/how-one-of-the-most-renowned-architects-in-history-accidentally-exposed-the-problems-of-central-planning/
  197. https://www.theguardian.com/cities/2015/apr/22/pruitt-igoe-high-rise-urban-america-history-cities
  198. https://www.researchgate.net/publication/353326787_Factors_that_contributed_to_the_failure_of_the_Pruitt-Igoe_Housing
  199. https://sites.utexas.edu/internationalplanning/case-studies/modernist-architecture-and-the-failures-of-place-making-in-brasilia/
  200. https://www.sciencedirect.com/science/article/pii/S2590198221001731
  201. https://www.sciencedirect.com/science/article/abs/pii/S2211464515300725
  202. https://www.newsweek.com/what-happened-china-ghost-cities-2047985
  203. https://www.ube.ac.uk/whats-happening/articles/ghost-cities/
  204. https://www.annualreviews.org/content/journals/10.1146/annurev-polisci-041322-041133
  205. https://urbanland.uli.org/issues-trends/zoning-reforms-to-mitigate-americas-affordable-housing-crisis
  206. https://nlihc.org/resource/study-finds-less-restrictive-zoning-regulations-increase-housing-supply-though-not
  207. https://pmc.ncbi.nlm.nih.gov/articles/PMC2987789/
  208. https://www.sciencedirect.com/science/article/pii/S0264275121001293
  209. https://journal-buildingscities.org/articles/10.5334/bc.125
  210. https://www.vitalcitynyc.org/articles/the-misunderstood-urban-nimby
  211. https://papers.ssrn.com/sol3/papers.cfm?abstract_id=5347083
  212. https://www.startribune.com/mpls-2040-plan-affordable-housing-policy-reform/601455039
  213. https://www.rand.org/pubs/commentary/2023/02/senate-bill-9s-underwhelming-first-year-shouldnt-be.html
  214. https://calmatters.org/housing/2025/02/california-yimby-laws-assessment-report/
  215. https://www.sciencedirect.com/science/article/pii/S1051137724000512
  216. https://www.pnas.org/doi/10.1073/pnas.1606035114
  217. https://www.zurich.com/knowledge/topics/global-risks/the-risks-of-rapid-urbanization-in-developing-countries
  218. https://www.aei.org/articles/the-real-impact-of-zoning-and-land-use-reforms-contrary-to-the-urban-institutes-claims/
  219. https://bipartisanpolicy.org/blog/comprehensive-zoning-reform-in-minneapolis-mn/
  220. https://journal-buildingscities.org/articles/10.5334/bc.130
  221. https://www.sciencedirect.com/science/article/pii/S0966692325002182
  222. https://www.forbes.com/sites/deloitte/2021/08/30/urban-transformation-post-pandemic-not-business-as-usual/
  223. https://www.oecd.org/en/topics/climate-and-resilience-in-cities.html
  224. https://resilientcitiesnetwork.org/investing-in-cities-strengthening-urban-resilience-finance/
  225. https://www.sciencedirect.com/science/article/pii/S2226585624001626
  226. https://pmc.ncbi.nlm.nih.gov/articles/PMC9477610/
  227. https://pmc.ncbi.nlm.nih.gov/articles/PMC8949457/
  228. https://www.researchgate.net/publication/359370013_Can_Digital_Transformation_Promote_the_Rapid_Recovery_of_Cities_from_the_COVID-19_Epidemic_An_Empirical_Analysis_from_Chinese_Cities
  229. https://www.telefonica.com/en/communication-room/blog/smart-cities-trends-shape-urban-future/
  230. https://www.deloitte.com/us/en/insights/industry/public-sector/smart-city-technology.html
  231. https://www.startus-insights.com/innovators-guide/emerging-smart-city-trends/
  232. https://www.unescap.org/kp/2025/urban-transformation-asia-and-pacific-growth-resilience
  233. https://www.undp.org/sites/g/files/zskgke326/files/2025-10/rethinking_urban_governance_single_pages_compressed.pdf
  234. https://unhabitat.org/asia-pacific-urban-transformations-shifting-from-quantity-to-quality
  235. https://publications.wri.org/transformations-equitable-sustainable-cities/current-urbanization-global-south-realities
  236. https://worldgbc.org/article/sustainable-and-affordable-housing/
  237. https://www.acash.org.pk/affordable-housing-crisis-in-megacities/
  238. https://www.naturebasedsolutionsinitiative.org/wp-content/uploads/2025/01/Mapping-the-effectiveness-of-nature%25E2%2580%2590based-solutions-for-climate-change-adaptation.pdf
  239. https://academic.oup.com/bioscience/article/69/6/455/5492440
  240. https://www.mdpi.com/2071-1050/15/9/7243
  241. https://urbanization.yale.edu/research/theme-4
  242. https://www.epa.gov/smartgrowth/about-smart-growth
  243. https://www.frontiersin.org/journals/climate/articles/10.3389/fclim.2025.1557352/full
  244. https://www.nature.com/articles/s42949-023-00113-0
  245. https://www.frontiersin.org/journals/sustainable-cities/articles/10.3389/frsc.2022.624046/full
  246. https://www.sciencedirect.com/science/article/pii/S0048969724053294
Add your contribution
Related Hubs
User Avatar
No comments yet.