Data play an increasingly important role in shaping competition, influencing how firms innovate, set prices, and interact with consumers. As data collection and analysis have expanded across the economy, competition authorities have increasingly examined when data promote efficiency and consumer welfare and when they may raise concerns related to market power or exclusionary conduct. 
 
In a recent article published in the California Bar Competition Journal, Senior Managing Director James Mellsop, Director John Scalf, and Senior Consultants Mark Ponder and Veronica Postal analyze how data have featured in recent US antitrust enforcement. Drawing on enforcement actions and litigation across a range of industries, they discuss three recurring theories of competitive harm—data as an input into product development, anticompetitive misuse of personal data, and access to competitively sensitive data to unfairly disadvantage rivals—and outline the economic principles regulators have applied in assessing competition in data-driven markets.