While it can be hard to evaluate a failing firm defense under the Merger Guidelines, the principles underlying the test are generally sound, even when the overall economy is going through very difficult times.

The author argues for using the total welfare standard, rather than the more commonly employed consumer welfare standard. In doing so, Heyer responds to three broad objections that have been raised.

The author argues for using the total welfare standard, rather than the more commonly employed consumer welfare standard. In doing so, Heyer responds to three broad objections that have been raised. Ken Heyer (Federal Trade Commission)

How have the revised Horizontal Merger Guidelines affected welfare standards in merger analysis? Ken Heyer (Federal Trade Commission)

Retrospective studies that ask whether prices went up post-merger are surprisingly poor guides for analyzing merger policy.

Tirole has written an excellent primer focused on what is known about tying and what he believes is desirable antitrust policy concerning the practice. Although the authors agree with most of Tirole’s arguments, there are two topics for which our perspective is somewhat different.

Market definition is a crude though sometimes useful tool for identifying market power. The ambiguity in what analysts mean by market power (price above marginal cost, or excess profits) cannot be resolved by market share.

This article is a transcript of the presentations given by Dennis Carlton and Michael Salinger at the University College London’s Annual Antitrust and Regulation Forum held on February 21, 2007 and hosted by the Jevons Institute for Competition Law and Economics.

Stigler’s theory of oligopoly remains a central pillar in merger policy in most, if not all, antitrust regimes around the world. Dennis Carlton & Sam Peltzman (Univ. of Chicago)