Evaluating Substitutes for Federal Antitrust: The Case of COPAs

Are state-imposed behavioral remedies effective substitutes for federal antitrust enforcement? We evaluate state regulation of hospital mergers under Certificates of Public Advantage (COPAs). Using hospital data from 1996-2022, we compare COPA-regulated mergers to unregulated mergers with similar anticompetitive potential. In highly concentrated markets, COPA mergers result in 11.1 p.p. lower price growth but 0.5 p.p. greater increases in 30-day mortality rates. We find a negative correlation between price and mortality effects for COPA mergers, consistent with theoretical predictions that binding price caps exacerbate quality deterioration. Our findings suggest that COPA contracts are poor substitutes for traditional antitrust enforcement.