Health insurers increasingly compete on their networks of medical providers. Using data from Massachusetts’s insurance exchange, I find substantial adverse selection against plans covering the most prestigious and expensive “star” hospitals. I highlight a theoretically distinct selection channel: consumers loyal to star hospitals incur high spending, conditional on their medical state, because they use these hospitals’ expensive care. This implies heterogeneity in consumers’ incremental costs of gaining access to star hospitals, posing a challenge for standard selection policies. Along with selection on unobserved sickness, I find this creates strong incentives to exclude star hospitals, even with risk adjustment in place. (JEL D82, G22, H75, I11, I13, I18)

中文翻译：

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医院网络竞争和逆向选择：来自马萨诸塞州健康保险交易所的证据

健康保险公司在其医疗服务提供者网络上的竞争日益激烈。使用来自马萨诸塞州保险交易所的数据，我发现针对涵盖最负盛名和最昂贵的“明星”医院的计划存在大量逆向选择。我强调了一个理论上不同的选择渠道：忠诚于星级医院的消费者会产生高额支出，这取决于他们的医疗状况，因为他们使用这些医院的昂贵医疗服务。这意味着消费者进入星级医院的增量成本存在异质性，对标准选择政策提出了挑战。除了对未观察到的疾病进行选择外，我发现这产生了排除星级医院的强烈动机，即使进行了风险调整。(JEL D82, G22, H75, I11, I13, I18)