Why Do People Keep Their Promises? An Experimental Test of Two Explanations
通过实验检验了两种解释承诺促进合作的理论：一是人们偏好守信，二是人们不愿让他人的收益预期落空。结果发现承诺的效果不能由收益预期变化解释，支持了守信偏好本身的存在。
Numerous psychological and economic experiments have shown that the exchange of promises greatly enhances cooperative behavior in experimental games. This paper seeks to test two theories to explain this effect. The first posits that individuals have a preference for keeping their word. The second assumes that people dislike letting down others' payoff expectations. According to the latter account, promises affect behavior only indirectly, because they lead to changes in the payoff expectations attributed to others. I conduct an experiment designed to distinguish between and test these alternative explanations. The results demonstrate that the effects of promises cannot be accounted for by changes in payoff expectations. This suggests that people have a preference for promise keeping per se. Copyright 2008 The Econometric Society.