The 2010 Merger Guidelines and the Litigation Mulligan: Better Economics but Not (Necessarily) More Clarity Before the Agencies and the Courts

The new Horizontal Merger Guidelines, issued by the U.S. antitrust Agencies on August 19, 2010, mark a clear change from their 1992 predecessor.They reduce the importance of traditional market definition, increase Herfindahl-Hirschman Index (“HHI”) thresholds, and expand the types of evidence considered. Most commentary to date has focused on the fact that the new Guidelines largely codify hitherto-unofficial (although widely known) practic