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...

This is a survey of the economic principles that underlie antitrust law and how those principles relate to competition policy. We address four core subject areas: market power, collusion, mergers between competitors, and monopolization. In each area, we select the most relevant portions of...

On September 4, 1996, the two largest office superstore chains in the United States, Office Depot and Staples, announced their agreement to merge. Seven months later, the Federal Trade Commission voted 4 to 1 to oppose the merger on the grounds that it was likely to harm competition and lead to...