Economics and Antitrust Enforcement: The Last 25 Years

Economics has reshaped antitrust enforcement over the last quarter century. Its impact has been most dramatic in merger analysis, with the shift toward unilateral effects theories and away from market concentration-related theories of collusion. Progress on both the theoretical and empirical fronts has also changed enforcement priors and competitive analyses concerning vertical restraints and monopolization. Economists also have made valuable assessments of the effectiveness of antitrust enforcement, though more work in this area is needed.