Reciprocity in multiple principals – one agent interactions: experimental evidence
通过信贷市场背景下的信任博弈实验，研究了当多个委托人（贷款人）同时与一个代理人（借款人）互动时，互惠行为如何变化。发现随着委托人数量增加，代理人的互惠性下降，原因是违约对每个委托人造成的边际伤害减小，且代理人对负面后果的敏感度降低。
Abstract Agents frequently engage with multiple principals simultaneously – for example, when borrowing from several banks or peers. In such settings, principals typically possess less information about the agent’s ability or intentions (e.g., to repay a loan) and must rely on trust. This paper presents experimental evidence from trust games framed in a credit market context to examine the role of reciprocity in interactions involving multiple principals (lenders) and a single agent (borrower). Agents were asked to decide whether to act trustworthily and repay, or to default and act selfishly, after receiving the same credit amount from either one or multiple principals. The results show that reciprocity declines when the number of trusting principals increases. A key mechanism appears to be the reduced marginal harm that an agent’s default imposes on each individual principal. Additionally, agents seem less sensitive to the negative consequences of their actions when multiple principals are affected. These findings suggest that interactions involving multiple principals are behaviorally riskier than bilateral ones. The results have implications for the design of incentive structures in multi-principal-agent environments, such as crowdlending platforms.