Entry and Competition in Concentrated Markets
提出一个实证框架，用于衡量集中市场中进入的影响，通过分析五个零售和专业行业的数据，研究企业数量、市场规模与竞争之间的关系。
This paper proposes an empirical framework for measuring the effects of entry in concentrated markets. Building on models of entry in atomistically competitive markets, the authors show how the number of producers in an oligopolistic market varies with changes in demand and market competition. These analytical results structure the authors' empirical analysis of competition in five retail and professional industries. Using data on geographically isolated monopolies, duopolies, and oligopolies, they study the relationship between the number of firms in a market, market size, and competition. The authors' empirical results suggest that competitive conduct changes quickly as the number of incumbents increases. Copyright 1991 by University of Chicago Press.