title: The revolution in health care antitrust: new methods and provocative implications.
abstract: BACKGROUND
  In recent years, federal courts have permitted hospital consolidations and other potentially anticompetitive actions by accepting hospitals' claims that they compete in expansive geographic markets. Recent events, including two actions by the U.S. Federal Trade Commission, suggest that antitrust is undergoing a sea change, thanks in part to new methods for defining geographic markets. This article reviews the recent history of hospital antitrust, describes the methods used to define markets, and illustrates the new methods by considering two consolidations recently proposed by a New York regulatory agency.
  
  
  METHODS
  The new methods for defining geographic markets rely on estimates from conditional choice models using patient-level hospitalization data. These estimates are the raw material for computations of price effects derived from a theoretical model of hospital pricing in a managed care environment.
  
  
  RESULTS
  Applying these methods to two proposed consolidations in New York shows that one of the mergers would likely raise prices by a substantial amount without the promise of offsetting efficiencies but that the other would not have this effect.
  
  
  CONCLUSIONS
  New methods for geographic market definition may fundamentally alter how courts will evaluate antitrust challenges. Although additional research is necessary to refine the predictions of these new methods, consolidating hospitals, as well as any other hospitals engaging in potentially anticompetitive conduct, can no longer anticipate a friendly reception in the courtroom.
authors.affiliation: Northwestern University, Kellogg School of Management, 2001 Sheridan Road, Evanston, IL 60208, USA. d-dranove@kellogg.northwestern.edu
authors.forename: David
authors.initials: D
authors.lastname: Dranove
authors.forename: Andrew
authors.initials: A
authors.lastname: Sfekas
mesh_terms: D016363:Antitrust Laws; D006273:Health Facility Merger / Q000191:economics / Q000331:legislation & jurisprudence; D007882:Legislation, Hospital; D009518:New York; D014481:United States; D014485:United States Federal Trade Commission / Q000331:legislation & jurisprudence