Professor Louis Kaplow has argued that market delineation in antitrust should be abandoned because it is not useful in assessing market power or evaluating competitive effects. This article takes issue with that view, explaining that market delineation serves purposes overlooked by Professor...

On January 10, 2022, the U.S. Department of Justice and Federal Trade Commission issued a Request for Information on Merger Enforcement designed to elicit input in the preparation of guidelines replacing both the 2010 Horizontal Merger Guidelines and the 2019 Vertical Merger Guidelines. The RFI...

In the competitive analysis of mergers, "calibrated economic models" are standard, formal models, particularly monopoly and oligopoly models, in which the values of the key parameters are set on the basis of observable features of the industry under review. Calibrated economic models offer three...

The U.S. Horizontal Merger Guidelines and guidelines issued by enforcement agencies around the world employ the hypothetical monopolist paradigm to delineate relevant markets, but they provide only an imprecise and incomplete algorithm for implementing that paradigm. This paper fills the gap by...

"Critical elasticity of demand" and "critical loss" analysis are now standard analytical tools for implementing the hypothetical monopolist paradigm for market delineation. Although these tools are highly useful, this paper presents three scenarios in which their standard application can be...

Owners of standard essential patents (SEPs) are cast as villains for engaging in “patent hold-up,” i.e., taking advantage of the fact that they negotiate royalties with implementer-licensees that already have made sunk investments in the standard. In contrast to “patent ambush,” patent...

Inconvenient truths prevent econometric merger retrospective studies from substantially altering our understanding of competitive effects from horizontal mergers. Econometrics cannot definitively determine the effects of particular mergers, and if they could, econometric merger retrospectives...

The New Brandeis School renews debate on two fundamental antitrust policy questions: 1) what source of wisdom or set of values should inform antitrust rules; and 2) what criterion should govern antitrust case adjudication. In our view, the Chicago School's answer to the first question was right;...

Official sources state that the Antitrust Division of the U.S. Department of Justice was created by Attorney General Homer S. Cummings in 1933, but no corroboration is provided. This note carefully examines the events of 1933 as well prior history, and it discovers that the Antitrust Division...