The U.S. Horizontal Merger Guidelines After One Half Century: Three Steps Forward and One Step Back

The U.S. antitrust agencies’ Horizontal Merger Guidelines are approaching their half century mark, having progressed through three earlier versions to their current 2010 form. Recent reports promote the contention that the enhanced sophistication and transparency of the newer versions have led to improved policy results. This study questions this conclusion by examining recent retrospective merger case evidence as well as agency policy and practices, in light of long-held Supreme Court dicta