We show in two natural experiments that default rules in Medicare Part D have large, persistent effects on enrollment and drug utilization of low-income beneficiaries. The implications of this phenomenon for welfare and optimal policy depend on the sensitivity of passivity to the value of the default option. Using random assignment to default options, we show that beneficiary passivity is extremely insensitive, even when enrolling in the default option would result in substantial drug consumption losses. A third natural experiment suggests that variation in active choice is driven by random transitory shocks rather than the inherent attentiveness of some beneficiaries.

中文翻译：

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违约效应的行为基础：医疗保险 D 部分的理论和证据。


我们在两个自然实验中表明，医疗保险 D 部分中的默认规则对低收入受益人的注册和药物使用具有巨大而持久的影响。这种现象对福利和最优政策的影响取决于被动性对默认期权价值的敏感性。通过对默认选项的随机分配，我们发现受益人的被动性极其不敏感，即使加入默认选项会导致大量的药物消耗损失。第三个自然实验表明，主动选择的变化是由随机的短暂冲击驱动的，而不是某些受益者固有的注意力。