Barriers to entry

In theories of competition in economics, a barrier to entry, or an economic barrier to entry, is a fixed cost that must be incurred by a new entrant, regardless of production or sales activities, into a market that incumbents do not have or have not had to incur. Because barriers to entry protect incumbent firms and restrict competition in a market, they can contribute to distortionary prices and are therefore most important when discussing antitrust policy. Barriers to entry often cause or aid the existence of monopolies and oligopolies, or give companies market power. Barriers of entry also have an importance in industries. First of all it is important to identify that some exist naturally, such as brand loyalty. Governments can also create barriers to entry to meet consumer protection laws, protecting the public. In other cases it can also be due to inherent scarcity of public resources needed to enter a market.

Various conflicting definitions of "barrier to entry" have been put forth since the 1950s. This has caused there to be no clear consensus on which definition should be used.

McAfee, Mialon, and Williams list seven common definitions in economic literature in chronological order including:

In 1956, Joe S. Bain used the definition "an advantage of established sellers in an industry over potential entrant sellers, which is reflected in the extent to which established sellers can persistently raise their prices above competitive levels without attracting new firms to enter the industry." McAfee et al. criticized this as being tautological by putting the "consequences of the definition into the definition itself."

In 1968, George Stigler defined an entry barrier as "A cost of producing that must be borne by a firm which seeks to enter an industry but is not borne by firms already in the industry." McAfee et al. criticized the phrase "is not borne" as being confusing and incomplete by implying that only current costs need be considered.

In 1979, Franklin M. Fisher gave the definition "anything that prevents entry when entry is socially beneficial." McAfee et al. criticized this along the same lines as Bain's definition.

In 1981, Baumol and Willig gave the definition "An entry barrier is anything that requires an expenditure by a new entrant into an industry, but that imposes no equivalent cost upon an incumbent"

In 1994, Dennis Carlton and Jeffrey Perloff gave the definition, "anything that prevents an entrepreneur from instantaneously creating a new firm in a market." Carlton and Perloff then dismiss their own definition as impractical and instead use their own definition of a "long-term barrier to entry" which is defined very closely to the definition in the introduction.