This handbook chapter appears in Antitrust Law & Economics (Keith Hylton, ed. 2010). It describes the role of market concentration in the legal framework for the antitrust review of horizontal mergers and evaluates the extent to which modern economic analysis supports a role for concentration in...

In 2013, a federal district court found that Apple had orchestrated a cartel agreement involving it and five major book publishers three years earlier, when Apple opened the iBookstore in conjunction with the introduction of its iPad tablet computer. According to the court, Apple organized...

When the 1968 Merger Guidelines were drafted, both the economics and antitrust literatures addressed how competition could be softened when oligopolists anticipated the natural and predictable responses of their rivals to their competitive moves, such as price cuts or output expansion. But when...

A contemporary consensus in antitrust discourse inappropriately places exclusionary conduct at the periphery of competition policy, while putting collusion at the core. Contrary to that common view, exclusion is as important as collusion as a matter of precedent, the structure of doctrinal...