This project aims to give state and federal regulators a legal and empirical foundation to assess the full impact of cross-market health care mergers. A team comprising economics experts at UC Berkeley, led by Richard Scheffler, and legal scholars at the UC Hastings College of Law, led by Jaime King, will: determine the size and scope of cross-market mergers; identify key factors from the legal and economic literature that may be relevant to their effects; estimate the impact of cross-market mergers on health care prices and quality; host a workshop to identify key criteria for determining the conditions that give rise to anticompetitive cross-market mergers; and propose evidence-based legal criteria to aid antitrust enforcers and judges in determining when proposed cross-market mergers are likely to be anticompetitive. The data for this analysis will be drawn from the Health Care Cost Institute on commercial prices, Medicare Hospital and Physician Compare, the American Hospital Association’s Annual Survey Database, and SK&A Office-based Provider Database.