Ha-Joon Chang (/tʃæŋ/; Korean: 장하준; born 7 October 1963) is a South Korean economist and academic. Chang specialises in institutional economics and development, and lectured in economics at the University of Cambridge from 1990–2021 before becoming professor of economics at the School of Oriental and African Studies (SOAS) in 2022. Chang is the author of several bestselling books on economics and development policy, most notably Kicking Away the Ladder: Development Strategy in Historical Perspective (2002). In 2013, Prospect magazine ranked Chang as one of the top 20 World Thinkers.

Chang has served as a consultant to the World Bank, the Asian Development Bank, the European Investment Bank, as well as to Oxfam and various United Nations agencies. He is also a fellow at the Center for Economic and Policy Research in Washington, D.C. In addition, Chang serves on the advisory board of Academics Stand Against Poverty (ASAP).

After graduating from Seoul National University's Department of Economics, he studied at the University of Cambridge, earning an MPhil and a PhD for his thesis entitled The Political Economy of Industrial Policy – Reflections on the Role of State Intervention in 1991. Chang's contribution to economics started while studying under Robert Rowthorn, a leading British Marxist economist, with whom he worked on the elaboration of the theory of industrial policy, which he described as a middle way between central planning and an unrestrained free market. His work in this area is part of a broader approach to economics known as institutionalist political economy which places economic history and socio-political factors at the centre of the evolution of economic practices.

In his book Kicking Away the Ladder (which won the European Association for Evolutionary Political Economy's 2003 Gunnar Myrdal Prize), Chang argued that all major developed countries used interventionist economic policies in order to get rich and then tried to forbid other countries from doing the same. The World Trade Organization, World Bank, and International Monetary Fund come in for strong criticism from Chang for "ladder-kicking" of this type which, he argues, is the fundamental obstacle to poverty alleviation in the developing world. This and other work led to his being awarded the 2005 Wassily Leontief Prize for Advancing the Frontiers of Economic Thought from the Global Development and Environment Institute (previous prize-winners include Amartya Sen, John Kenneth Galbraith, Herman Daly, Alice Amsden and Robert Wade).

The book's methodology was criticized by American Douglas Irwin, Professor of Economics at Dartmouth College and author of a 2011 study of the Smoot–Hawley tariff, writing on the website of the Economic History Association:

Chang only looks at countries that developed during the nineteenth century and a small number of the policies they pursued. He did not examine countries that failed to develop in the nineteenth century and see if they pursued the same heterodox policies only more intensively. This is a poor scientific and historical method. Suppose a doctor studied people with long lives and found that some smoked tobacco, but did not study people with shorter lives to see if smoking was even more prevalent. Any conclusions drawn only from the observed relationship would be quite misleading.

Chang countered Irwin's criticisms by arguing that countries that had failed to develop had generally followed free market policies. Chang also argued that while state interventionism sometimes produced economic failures, it had a better record than unregulated free market economies which, he maintained, very rarely succeeded in producing economic development. He cited evidence that GDP growth in developing countries had been higher prior to external pressures recommending deregulation and extended his analysis to the failures of free trade to induce growth through privatisation and anti-inflationary policies. Chang's book won plaudits from Nobel Prize–winning economist Joseph Stiglitz for its fresh insight and effective blend of contemporary and historical cases but was criticised by former World Bank economist William Easterly, who said that Chang used selective evidence in his book. Chang responded to Easterly's criticisms, asserting that Easterly misread his argument. Easterly in turn provided a counter-reply.

Stanley Engerman, Professor of Economic History at University of Rochester praised Chang's approach: