Gilbert considers both theory and available empirical evidence on the relationships among market structure, firm behavior, and the production of new products and services. He reviews the distinctive features of the high-tech economy and why current analytical tools used by antitrust enforcers aren't up to the task of assessing innovation concerns. He considers, from the perspective of innovation competition, Kenneth Arrow's “replacement effect” and the Schumpeterian theory of market power and appropriation; discusses the effect of mergers on innovation and future price competition; and reviews the empirical literature on competition, mergers, and innovation. He describes examples of merger enforcement by US and European antitrust agencies; examines cases brought against Microsoft and Google; and discusses the risks and benefits of interoperability standards. Finally, he offers recommendations for competition policy.