Abstract：
Unethical behavior is discovered that is more contagious than ethical behavior. This article attempts to propose one of the possible underlying mechanisms-people may have underconfidence bias in information updating due to motivated reasoning, and such bias exhibits in a different direction compared to the overconfident bias documented in the literature on ethical environment, which generate the asymmetric pattern in contagion. This study designs an experiment which relates the unethical behavior to social learning, where a series of subjects with private information about penalty decide sequentially whether to conduct unethical behavior publicly. This study adopts a quantal response equilibrium to construct a structural model for estimation of the bias. In total, 162 university students participated in our experiment and the results confirm the asymmetric patterns that people rely more on others\' precedent decisions rather than their private signal; therefore, the bias facilitates the contagion. This study also tests two punishment systems in the experiment and the results suggest a policy: slightly increasing penalties for the \"followers\" in the early stages would effectively suppress the contagion.
摘要：
发现不道德的行为比道德行为更具传染性。本文试图提出一种可能的潜在机制-人们可能由于动机推理而在信息更新中存在不自信偏见，与伦理环境文献中记录的过度自信偏见相比，这种偏见表现出不同的方向，在传染中产生不对称模式。这项研究设计了一个实验，将不道德行为与社会学习联系起来，其中一系列具有有关处罚的私人信息的受试者依次决定是否公开进行不道德行为。本研究采用定量响应平衡来构建结构模型以估计偏差。总的来说,162名大学生参加了我们的实验，结果证实了人们更多地依赖他人的先例决定而不是他们的私人信号的不对称模式；因此，偏见促进了传染。这项研究还测试了实验中的两种惩罚系统，结果提出了一项政策：在早期阶段稍微增加对“追随者”的惩罚将有效地抑制传染。
