Competition policy has become more prominent while the thinking underlying those policies has undergone substantial revision. We survey advances in antitrust economics and the economics of regulation. Increasing reliance on non-cooperative game theory as a foundation for antitrust has led to rethinking conventional approaches. We review some of these contributions in the context of mergers, vertical restraints, and competition in "network industries." Turning to regulation, we review standard rationales and identify some major contemporary refinements, with examples of the motives behind them and their application. After brief thoughts on privatization, we conclude with suggestions on design and implementation, with some observations on whether these developments are as valuable in the corridors of policy as they may be in the halls of academe.