Philadelphia National Bank: Bad Economics, Bad Law, Good Riddance

21 Pages Posted: 5 Aug 2016

See all articles by Douglas H. Ginsburg

Douglas H. Ginsburg

U.S. Court of Appeals for the District of Columbia Circuit; George Mason University - Antonin Scalia Law School

Joshua D. Wright


Date Written: August 3, 2016


In a series of five merger cases from 1962 through 1974, the Supreme Court turned the then-reigning Structure-Conduct-Performance paradigm into the law of the land. The Court has not passed upon the substantive aspect of merger analysis since then. Thus, the legacy of these cases, in particular, Philadelphia National Bank (PNB), endures: The plaintiff, ordinarily the Government, satisfies its prima facie burden by showing the merged firm would account for 30 percent or more of the relevant market, which shifts to the merging parties the burden of showing competition in the market will not be diminished notwithstanding the increase in concentration. The practical effect of the PNB presumption is to shift the burden of proof from the plaintiff, where it rightfully resides, to the defendant, without requiring evidence – other than market shares – that the proposed merger is likely to harm competition. The problem for today’s courts in applying this semicentenary standard is that the field of industrial organization economics has long since moved beyond the structural presumption upon which the standard is based. That presumption is almost the last vestige of pre-modern economics still embedded in the antitrust law of the United States. Even the 2010 Horizontal Merger Guidelines issued jointly by the Federal Trade Commission and the Antitrust Division of the Department of Justice have abandoned the 30 percent presumption, though the agencies certainly do not resist the temptation to rely upon the presumption when litigating a case. There is no doubt the 30 percent presumption of PNB is a convenient litigation tool for the enforcement agencies, but the mission of the enforcement agencies is consumer welfare, not cheap victories in litigation. The presumption ought to go the way of the agencies’ policy decision to drop reliance upon the discredited antitrust theories approved by the courts in such cases as Brown Shoe, Von’s Grocery, and Utah Pie. Otherwise, the agencies will ultimately have to deal with the tension between taking advantage of a favorable presumption in litigation and exerting a reformative influence on the direction of merger law.

Keywords: Administrative Law, Antitrust, Competition, Economics, Empirical, Enforcement, Federal Agencies, Federal Courts, Federal Trade Commission, Litigation, Market Share, Merger, U.S. Supreme Court

JEL Classification: K2, K21

Suggested Citation

Ginsburg, Douglas H. and Wright, Joshua D., Philadelphia National Bank: Bad Economics, Bad Law, Good Riddance (August 3, 2016). George Mason Law & Economics Research Paper No. 16-30, Antitrust Law Journal, Vol. 80, No. 2, 2015, Available at SSRN: or

Douglas H. Ginsburg (Contact Author)

U.S. Court of Appeals for the District of Columbia Circuit ( email )

333 Constitution Ave NW
Room 5523
Washington, DC 20001
United States

George Mason University - Antonin Scalia Law School ( email )

3301 Fairfax Drive
Arlington, VA 22201
United States

Joshua D. Wright

Independent ( email )

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