We study the emergence of norms and their enforcement in a public goods game with private information about endowments. Subjects were randomly assigned a Low or High endowment and, across treatments, endowments were either Observed or Unobserved. In both treatments subjects could enforce contributions with peer punishment. We use punishment decisions to estimate contribution norms and then estimate the expected costs of noncompliance. In Observed, both Low and High types enforce a “contribute-your-endowment” norm, adjusting the costs of noncompliance to account for each type’s endowment. In Unobserved we find that groups adapt to incomplete information by adopting a “contribute-the-Low-endowment” norm, and our expected cost calculations suggest that the enforcement of this norm balances the benefits of cooperation with the risk of misguided punishment. When at least one High type pools with Low types (by contributing less than or equal to the Low endowment), contributions of zero are punished as if they come from a High type, while contributions equal to the Low endowment are not punished in expectation (in case they come from a cooperative Low type). This enforcement strategy prevents cooperation from unraveling, but it also enables High types to hide behind the Low endowment. Our results dovetail with results from bargaining games and suggest that in settings with incomplete information, norms can attenuate but not eliminate non-cooperative behavior.

我们在具有关于禀赋的私人信息的公共产品博弈中研究规范的出现及其执行。受试者被随机分配一个低或高禀赋和跨越治疗，捐赠要么观测或不可观测。在两种治疗中，受试者都可以通过同伴惩罚来强制执行贡献。我们使用惩罚决策来估计贡献规范，然后估计不合规的预期成本。在Observed 中，Low和High类型都执行“贡献你的禀赋”规范，调整不合规成本以解释每种类型的禀赋。在未被观察到我们发现群体通过采用“贡献低禀赋”规范来适应不完整信息，我们的预期成本计算表明，该规范的执行平衡了合作的好处与误导性惩罚的风险。当至少一个High类型池具有Low类型（通过贡献小于或等于Low禀赋）时，零贡献被惩罚，就好像它们来自High类型一样，而等于Low禀赋的贡献在期望中不会受到惩罚（以防它们来自合作的低型）。这种执行策略可以防止合作瓦解，但它也使高隐藏在低禀赋背后的类型。我们的结果与讨价还价游戏的结果相吻合，并表明在信息不完整的环境中，规范可以减弱但不能消除非合作行为。