Market Delineation and the Justice Department’s Merger Guidelines

On June 14, 1982, the U. S. Department of Justice released new Merger Guidelines which outline its approach to enforcing section 7 of the Clayton Act. Perhaps the most innovative and important aspect of the Guidelines is their approach to market delineation. Gregory Werden, who was intimately involved in the preparation of the Guidelines, explores the practical applications of the Guidelines' market delineation principles. He finds that the Guidelines provide no rules for delineating markets but nevertheless make a major contribution by providing a coherent conceptual framework for thinking about the issues.