The hypothetical monopolist test has been used to define antitrust markets for over 20 years. However, many of these applications occur within the enforcement agencies and thus the implementation process is not fully transparent to antitrust practitioners. This paper provides a study of 116...

To be admissible in federal court under the Daubert standard, expert economic testimony must be (1) based on scientific analysis and (2) aid the dispute resolution process. Expert evidence should be considered scientific when (1) it meets Karl Popper’s falsification standard and (2) some...

Economists have two basic methodologies: structuralism, in which formal economic models control the analysis, and experimentalism, in which economic theory guides the analysis, but data from experiments determines the policy recommendation. The choice between the two approaches is often quite...

While the Merger Guidelines structure represents the standard approach to merger analysis in the US, economists have proposed methods to dispense with market definition and estimate the competitive effect directly. In this note, we argue that market definition is necessary to evaluate the...

The 2010 Merger Guidelines appear to elevate game theoretic models of competitive concerns to the primary concern of merger policy, while reducing the importance of market definition. Although situations in which this change makes some sense exist, we observe that, as a practical matter, market...

In the Microsoft case, the Department of Justice (DOJ) applied Post-Chicago theories of strategic behavior to anecdotal evidence of Microsoft's behavior and obtained a judgment against specific conduct. This paper takes a critical look at the theories of the case and the industry facts to...

Barriers to entry are a necessary, but not sufficient condition for a merger to adversely affect competition. As a barrier definition must be linked to the specific theory of competitive concern under review to be meaningful, a theoretical barrier definition is unlikely to be useful. Instead, an...

The Merger Guidelines highlight unilateral effects analysis as the most prominent theory of concern in differentiated markets. This study evaluates the Federal Trade Commission's historical record to determine what considerations drive the review process, if these considerations depend on the...

This paper empirically analyzes the Federal Trade Commission's merger enforcement decisions, to supplement the 2004 release of the Horizontal Merger Investigation Data. The study provides insights into the review process for both multi- and single-market mergers. We present concentration-based...

This paper presents an analysis of merger enforcement at the Federal Trade Commission under the 1992 Merger Guidelines. Econometric analysis suggests that enforcement decisions are best predicted with the Herfindahl when the relevant theory is collusion and the number of significant rivals when...