Quarterly Journal of Economics · 2021 · Jason Abaluck、Mauricio Caceres Bravo、Peter Hull、Amanda Starc
中文摘要
如果消费者无法识别高质量的保险计划，健康保险市场中的竞争可能无法改善健康结果。我们构建并应用了一种新颖的工具变量框架，以量化不同保险计划之间因果死亡率效应的差异，以及消费者对这种差异的关注程度。我们首先记录了本地市场内联邦医疗保险优势计划（Medicare Advantage）之间观测死亡率的巨大差异。随后我们表明，当死亡率较高（较低）的计划退出这些市场时，参保者往往会转向更为典型的计划，此后其死亡率会降低（升高）。我们推导并验证了一个新颖的“后备选择条件”，该条件支配受计划退出影响者之后的选择。当后备选择条件得到满足时，可以利用计划终止来估计观测到的计划死亡率与因果死亡率效应之间的关系。应用这一框架后，我们发现，计划死亡率能够无偏地预测因果死亡率效应。随后，我们扩展该框架，以研究计划死亡率效应的其他预测指标，并估计消费者的支付意愿。支出较高的计划往往会降低参保者的死亡率，但现有质量评级与计划的死亡率效应不相关。消费者在选择计划时很少重视死亡率效应。优质保险计划可大幅降低死亡率，而引导消费者转向此类计划可能改善受益人的健康状况。
Abstract
Competition in health insurance markets may fail to improve health outcomes if consumers are not able to identify high quality plans. We develop and apply a novel instrumental variables framework to quantify the variation in causal mortality effects across plans and how much consumers attend to this variation. We first document large differences in the observed mortality rates of Medicare Advantage plans within local markets. We then show that when plans with high (low) mortality rates exit these markets, enrollees tend to switch to more typical plans and subsequently experience lower (higher) mortality. We derive and validate a novel "fallback condition" governing the subsequent choices of those affected by plan exits. When the fallback condition is satisfied, plan terminations can be used to estimate the relationship between observed plan mortality rates and causal mortality effects. Applying the framework, we find that mortality rates unbiasedly predict causal mortality effects. We then extend our framework to study other predictors of plan mortality effects and estimate consumer willingness to pay. Higher spending plans tend to reduce enrollee mortality, but existing quality ratings are uncorrelated with plan mortality effects. Consumers place little weight on mortality effects when choosing plans. Good insurance plans dramatically reduce mortality, and redirecting consumers to such plans could improve beneficiary health.