Ex Post Review: An Under-Used Tool in the Antitrust Enforcement Toolkit

This paper addresses the costs and benefits of ex post review of competition enforcement. We consider both ex post review of potential anticompetitive activity itself as well as ex post review of agency decisions. We note that in many situations, ex post review can provide superior information that can improve either the instant enforcement decision or improve future enforcement decisions either by providing more information to the agencies or to the courts. We also discuss some more subtle effe