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...

Switching costs and network effects bind customers to vendors if products are incompatible, locking customers or even markets in to early choices. Lock-in hinders customers from changing suppliers in response to (predictable or unpredictable) changes in efficiency, and gives vendors lucrative ex...

Three years ago, the Antitrust Division and the Federal Trade Commission revised their Horizontal Merger Guidelines to articulate in greater detail how they would treat claims of efficiencies associated with horizontal mergers: claims that are frequently made, as for instance in the recently...