There seems to be consensus that the Department of Justice's 1984 Vertical Merger Guidelines do not reflect either modern theoretical and empirical economic analysis or current agency enforcement policy. Yet widely divergent views of preferred enforcement policies have been expressed among...

Economists widely agree that, absent sufficient efficiencies or other offsetting factors, mergers that increase concentration substantially are likely to be anticompetitive. Further, holding everything else equal, the magnitude of anticompetitive effects tends to be larger, the larger is the...

The FCC’s analysis of the Comcast-NBCU transaction fills a gap in the contemporary treatment of vertical mergers by providing a roadmap for courts and litigants addressing the possibility of anticompetitive exclusion. The FCC identified the factors any judicial or administrative tribunal would...

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...

The past forty years have witnessed a remarkable transformation in horizontal merger enforcement in the United States. With no change in the underlying statute, the Clayton Act, the weight given to market concentration by the federal courts and by the federal antitrust agencies has declined...

This article takes a fresh look at a longstanding issue in antitrust economics and policy: the problem of oligopoly coordination. First, it explains why coordinated conduct in oligopoly markets is a serious problem and an appropriate concern of antitrust enforcement. It shows that empirical...