Creating a More Inclusive and Sustainable Future

Tracking-Based Advertising After Apple's App Tracking Transparency: Firm-Level Evidence and Policy Implications
TechREG CHRONICLE, November 2025

We discuss the impact of Apple’s App Tracking Transparency's (“ATT”) on targeted, online advertising. We overview the empirical results of Aridor, Che, Hollenbeck, Kaiser & McCarthy (2025) that measured the impact of ATT on e-commerce firms. The results point to a large reduction in the efficacy of targeted advertising and subsequently large revenue losses, borne primarily by smaller firms. We discuss the competition policy implications of this by highlighting the potentially anticompetitive implications of privacy measures implemented by private firms and the lack of substitutability between advertising networks, despite a large exogenous shock in the efficacy of Meta advertising.

Aridor, Guy: Assistant Professor of Marketing, Northwestern University
Hollenbeck, Brett: Associate Professor of Marketing, UCLA
McCarthy, Daniel: Associate Professor of Marketing, University of Maryland

• Consumer Privacy
• Digital Marketing
• Digital Platforms
• Fairness and Equity