The impact of ownership on health care services in HMOs.

Tests the theory that owners (hospital, physician, insurance) of vertically integrated health maintenance organizations (HMOs) might substitute towards production of their own specialty goods. Uses data from various sources in the USA. Determines the impact of ownership on factors such as average physician ambulatory services per enrollee and average hospital days per enrollee. Concludes that policymakers need to encourage the development of standard publicly available quality measures to intensify competition and eliminate excess profits accruing to provider-owners who substitute towards production of their own goods.