Is Hospital Competition Socially Wasteful?
研究1985至1994年间医院竞争对医保患者心脏病治疗的影响，发现竞争的社会福利效应在1980年代不明确，但1990年代明确改善福利，且HMO参保率上升部分解释了这一变化。
We study the consequences of hospital competition for Medicare beneficiaries' heart attack care from 1985 to 1994. We examine how relatively exogenous determinants of hospital choice such as travel distances influence the competitiveness of hospital markets, and how hospital competition interacts with the influence of managed-care organizations to affect the key determinants of social welfare—expenditures on treatment and patient health outcomes. In the 1980s the welfare effects of competition were ambiguous; but in the 1990s competition unambiguously improves social welfare. Increasing HMO enrollment over the sample period partially explains the dramatic change in the impact of hospital competition.