Over the past several decades, consolidation among health care providers and insurers has increased their market power and driven up health care prices and premiums. In a new study, Brent D. Fulton, Daniel R. Arnold, and Richard M. Scheffler of the U.C. Berkeley School of Public Health look at health care provider and insurance market concentration for each metropolitan statistical area. For providers, the vast majority of these areas were at the concentrated end of the spectrum; for insurers, nearly all fell into the middle.
