Antitrust populists increasingly call on the government to “break up big tech.” But antitrust enforcers would face heavy evidentiary burdens if they sought to break a company up on the premise that a long-consummated merger was unlawful from the outset and should have been blocked years ago....

The FTC has enjoyed great success for decades, and I address four topics here in this paper presented at the opening session of the FTC's “Hearing on Competition and Consumer Protection in the 21st Century.” First, what durable success means for an agency like the FTC. Then, the vision I...

Critics from both the right and the left claim that modern antitrust doctrine, rooted in consumer welfare, is inadequate to handle the challenges of the twenty-first century economy. They express nostalgia for 1960s antitrust, when the field had no clear objectives and cases were decided on...

The antitrust agencies typically find customer reactions probative of the likely competitive effects of a merger. Thus, merger challenge data released by the FTC reveal that strong complaints from customers almost always lead to a government challenge. Nevertheless, some judges have been quite...