The relationship between competition and innovation is the subject of a familiar controversy in economics, between the Schumpeterian view that monopolies favor innovation and the opposite view, often associated with Kenneth Arrow, that competition favors innovation. Taking their cue from this debate, some commentators reserve judgment as to whether antitrust enforcement is good for innovation. Such misgivings are unnecessary. The modern economic learning about the connection between competition and innovation helps clarify the types of firm conduct and industry settings where antitrust interventions are most likely to foster innovation. Measured against this standard, contemporary competition policy holds up well. Today\u27s antitrust insti...