Empirical Economic Analysis in Antitrust Litigation — FTC v. Meta and Beyond

Compass Lexecon convened a group of premier economists in Washington, DC, to highlight lessons from the recent FTC v. Meta case on the use of field research and to discuss trends in antitrust economics. Compass Lexecon was retained to act as consultants and experts by Meta and its counsel, Kellogg, Hansen, Todd, Figel & Frederick PLLC. Several of the panelists at the event testified in the case or supported the litigation, which was decided in Meta’s favor in November 2025.

This invitation-only gathering of antitrust attorneys and economists participated in lively discussions on "Empirical Analysis and Field Experiments in Litigation” and "Empirical Analyses and Market Definition - The Impact of the FTC v. Meta Ruling on Litigation in High Tech Cases and Merger Review."

Key takeaways:

- FTC v. Meta is a defeat for the recent antitrust policy that has sought to demote the use of economic tools and elevate reliance on qualitative evidence based on older cases such as Brown Shoe.

- The experimental results enabled the application of traditional competition tools and highlight the need for empirical analysis and economic modelling in antitrust analysis and market definition.

- There is value in economic analysis and randomized experiments for:

• Measuring effects of conduct
• Predicting effects of remedies
• The existing frameworks for market definition and competitive effects analysis will need to account for the distinctive economics of AI markets.

The Compass Lexecon panelists included 2026 GCR Economist of the Year nominee John List, Hunt Allcott, Antonio Rangel, Dennis Carlton, Luís Cabral, and Anindya Ghose. Niall MacMenamin and Mary Coleman, head of US Antitrust at Compass Lexecon, were the event hosts.