Pace Law Review Volume 34 Issue 2 Spring 2014 Article 8 April 2014 When Bigger Is Better: A Critique of the Herfindahl-Hirschman Index’s Use to Evaluate Mergers in Network Industries Toby Roberts Follow this and additional works at: https://digitalcommons.pace.edu/plr Part of the Antitrust and Trade Regulation Commons, and the Business Organizations Law Commons Recommended Citation Toby Roberts, When Bigger Is Better: A Critique of the Herfindahl-Hirschman Index’s Use to Evaluate Mergers in Network Industries, 34 Pace L. Rev. 894 (2014) Available at: https://digitalcommons.pace.edu/plr/vol34/iss2/8 This Article is brought to you for free and open access by the School of Law at DigitalCommons@Pace. It has been accepted for inclusion in Pace Law Review by an authorized administrator of DigitalCommons@Pace. For more information, please contact
[email protected]. When Bigger Is Better: A Critique of the Herfindahl-Hirschman Index’s Use to Evaluate Mergers in Network Industries Toby Roberts* I. Introduction The Herfindahl-Hirschman Index (“HHI”) operates under a very simple premise: industry behavior strongly correlates with industry structure; the larger a firm is within its industry, the more likely it is to engage in supracompetitive pricing or other anticompetitive conduct.1 For more than 30 years, antitrust regulators have used the index to gauge whether prospective mergers would produce a firm of such magnitude that it would adversely impact societal welfare. When an HHI analysis of an impending merger suggests that a potentially harmful increase in concentration will result, the companies involved must demonstrate that the merger has other characteristics that mitigate its impact on prices in order to gain regulatory approval.2 * Staff attorney at the California Court of Appeal and former law clerk at the United States District Court for the Central District of California and the United States Court of Appeals for the Ninth Circuit.