Establishing Market and Monopoly Power in Tech Platform Antitrust Cases

Abstract

In June 2021, a federal judge dismissed the Federal Trade Commission’s first monopolization complaint against Facebook on the grounds that it did not plead sufficient facts to establish that Facebook possesses monopoly power in online social networking. The ruling highlights two contentious aspects of antitrust jurisprudence: the legal necessity of establishing a defendant’s monopoly power as part of Sherman Act liability for unilateral conduct, and of establishing market power as part of liability for some forms of multi-lateral conduct, as well as the few mechanisms available to plaintiffs in both public and private enforcement to accomplish that, especially following Ohio v. American Express. This article makes two related claims: that direct evidence of market power is plentiful and should be understood as such by courts, and that exactly the direct evidence of market power that courts should consider also establishes that relevant markets on each side of tech platforms are small when properly defined, whatever defendants may say.