Recent research in contract theory on the effects of behavioral biases implicitly assumes that they are stable, in the sense of not being affected by the contracts themselves. In this paper, we provide evidence that this is not necessarily the case. We show that in an insurance context, being insured against losses that may be incurred in a real-effort task changes subjects' self-confidence. Our novel experimental design allows us to disentangle selection into insurance from the effects of being insured by randomly assigning coverage after subjects revealed whether they want to be insured or not. We find that uninsured subjects are underconfident while those that obtain insurance have well-calibrated beliefs. Our results suggest that there might be another mechanism through which insurance affects behavior than just moral hazard.

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有保险会改变个人的自信吗？

最近关于行为偏差影响的合同理论研究隐含地假设它们是稳定的，即不受合同本身的影响。在本文中，我们提供的证据表明情况并非如此。我们表明，在保险背景下，为实际努力任务中可能发生的损失投保会改变受试者的自信心。我们新颖的实验设计使我们能够通过在受试者透露他们是否想要投保后随机分配保险范围，将选择与投保的影响分开。我们发现未投保的受试者缺乏自信，而获得保险的受试者则具有良好校准的信念。我们的研究结果表明，保险影响行为的机制可能不仅仅是道德风险。