Event Studies and the Analysis of Antitrust

A standard tool in economics and finance is the event study in which one examines the impact of an event on stock returns. While hundreds of such studies have been published, the concern here is with a small subset: the use of event studies to examine antitrust issues. After a brief review of the event study technique, we provide a review of the literature that is the nexus of event studies and antitrust. The goal is to not only chronicle the development of this literature and highlight the major findings, but also to comment on important issues concerning implementation of this research method and the interpretation of the results.