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...

Gasoline prices increased dramatically in the U.S. Midwest in the summer of 2000, generating allegations of collusion among gasoline marketers. We examine the causes of the price increase, and find no evidence to support the collusion story. Instead, a combination of industry characteristics and...

For the purpose of explaining interindustry variation in the geographic distribution of firms, we explore the impact of product heterogeneity on the incentives for firms to cluster in the presence of a ubiquitous "periphery" of stand-alone firms. Our analysis revolves around two counteracting...