David Evans, Richard Schmalensee, Apr 19, 2007
Many diverse industries are populated by businesses that operate “two-sided platforms.” These businesses serve distinct groups of customers who need each other in some way, and the core business of the two-sided platform is to provide a common (real or virtual) meeting place and to facilitate interactions between members of the two distinct customer groups. Platforms play an important role throughout the economy by minimizing transactions costs between entities that can benefit from getting together. In these businesses, pricing and other strategies are strongly affected by the indirect network effects between the two sides of the platform. As a matter of theory, for example, profit-maximizing prices may entail below-cost pricing to one set of customers over the long run and, as a matter of fact, many two-sided platforms charge one side prices that are below marginal cost and are in some cases negative. These and other aspects of two-sided platforms affect almost all aspects of antitrust analysis from market definition, to the analysis of cartels, single-firm conduct, and efficiencies. This paper provides a brief introduction to the economics of two-sided platforms and the implications for antitrust analysis.