The Output-Welfare Fallacy: A Modern Antitrust Paradox

57 Pages Posted: 23 Jun 2021 Last revised: 24 Mar 2022

See all articles by John M. Newman

John M. Newman

University of Miami - School of Law

Date Written: June 14, 2021


A fallacy lies at the core of modern antitrust. The same scholars who successfully advanced a singular consumer-welfare goal simultaneously argued that output effects should be the exclusive criterion for analysis. This output–welfare framework entered mainstream discourse, was endorsed by enforcers and judges, and played a pivotal role in the Supreme Court’s recent Ohio v. American Express opinion. Yet despite its centrality, outputism has largely escaped notice.

When exposed to systematic evaluation, the previously assumed link between output and welfare breaks down. A wide variety of conduct can push output and welfare in opposite directions. Moreover, purely outputist analysis is often unworkable in markets—for labor, social networking, online search, and more—that are of particular interest to contemporary antitrust.

Recognizing the Output–Welfare Fallacy offers substantial payoffs. It illuminates and undercuts the fundamental illogic that motivates outputist judicial decisions, which warrant swift reversal. Market power can be defined as the power to control competition, rather than power to profitably reduce output. Plaintiffs need not demonstrate an output reduction to carry their initial burden of proof. Conversely, defendants need not prove that output increased in order to make out a valid procompetitive justification. In general, moving beyond the narrow confines of output-based analysis enables the application of a more coherent, practical, and efficient antitrust framework.

Keywords: antitrust, output, consumer welfare, law and economics, tying, monopolization, restraints of trade, anticompetitive effects, rule of reason, procompetitive justifications

JEL Classification: D21, D41, D42, D61, D62, K21, L4, L40, L41, L42, L43, L44

Suggested Citation

Newman, John M., The Output-Welfare Fallacy: A Modern Antitrust Paradox (June 14, 2021). 107 Iowa L. Rev. 563 (2022), University of Miami Legal Studies Research Paper No. 3866725, Available at SSRN: or

John M. Newman (Contact Author)

University of Miami - School of Law ( email )

P.O. Box 248087
Coral Gables, FL 33146
United States

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