Price competition and hospital cost growth in the United States (1989-1994)
利用美国全国数据，研究发现健康维护组织和优选提供组织在竞争性医院市场中显著抑制了成本增长，但在集中市场中效果不明显，且健康维护组织比优选提供组织更有效。
In recent years, most health care markets in the United States (US) have experienced rapid penetration by health maintenance organizations (HMOs) and preferred provider organizations (PPOs). During this same period, the US has also experienced slowing health care costs. Using a national database, we demonstrate that HMOs and PPOs have significantly restrained cost growth among hospitals located in competitive hospital markets, but not so in the case of hospitals located in relatively concentrated markets. In relative terms, we estimate that HMOs have contained cost growth more effectively than PPOs.