U.S. antitrust law empowers enforcers to review pending mergers that might undermine competition. But there is growing evidence that the merger-review regime is failing to perform its core procompetitive function. Industry concentration and the power of dominant firms are increasing across key...

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...