The Wharton School, University of Pennsylvania, Philadelphia, PA 19104.
The Wharton School, University of Pennsylvania, Philadelphia, PA 19104
Proc Natl Acad Sci U S A. 2018 Feb 20;115(8):1766-1771. doi: 10.1073/pnas.1708293115. Epub 2018 Feb 7.
We examine how reciprocity changes over time by studying a large quasiexperiment in the field. Specifically, we analyze administrative data from a university hospital system. The data include information about over 18,000 donation requests made by the hospital system via mail to a set of its former patients in the 4 months after their first hospital visit. We exploit quasiexperimental variation in the timing of solicitation mailings relative to patient hospital visits and find that an extra 30-day delay between the provision of medical care and a donation solicitation decreases the likelihood of a donation by 30%. Our findings have important implications for models of economic behavior, which currently fail to incorporate reciprocity's sensitivity to time. The fact that reciprocal behavior decays rapidly as time passes also suggests the importance of capitalizing quickly on opportunities to benefit from a quid pro quo.
我们通过研究一个大型的现场准实验来研究互惠关系随时间的变化。具体来说，我们分析了一家大学医院系统的行政数据。这些数据包括了医院系统通过邮件向其一组前患者发送的 18000 多个捐赠请求的信息，这些请求是在患者首次就诊后的 4 个月内发出的。我们利用请求邮件的发送时间与患者就诊时间之间的准实验性差异，发现医疗服务提供和捐赠请求之间的时间间隔每增加 30 天，捐赠的可能性就会降低 30%。我们的发现对经济行为模型具有重要意义，因为这些模型目前未能将互惠关系对时间的敏感性纳入其中。互惠行为随时间迅速衰减的事实也表明，利用互惠机会迅速获益非常重要。
