可退还押金：如何在有限重复博弈中恢复合作
Refundable Deposits: How to Restore Cooperation in Finitely Repeated Games
AI总结：
该研究提出一种可退还押金机制，通过中立中介的押金规则，在囚徒困境等无法自发合作的有限重复博弈中恢复合作，提升效率，且适用范围可扩展至动态公共池塘资源。
AI中文摘要：
无限重复博弈可产生丰富的纳什均衡集合，而有限重复博弈的纳什均衡集合通常小得多且往往效率低下。我们展示了如何利用押金扩大该集合：在每一轮博弈中，参与者可向中立中介机构存入一笔可退还的款项，该款项在博弈结束时返还，若出现偏离则被没收。支付押金是自愿的，且在每一个阶段都满足激励相容，因此无需假设参与者做出承诺，唯一需要的承诺是中介机构在博弈开始前确定的退款规则。该机制维持的收益状况比标准均衡的收益状况更有效，且不改变基础博弈，也无需参与者之间的转移支付。我们在囚徒困境、拥塞博弈和公共物品博弈中验证了这一点，这些博弈的标准有限重复版本中无法出现合作。我们还将其应用于动态公共池塘资源，表明该机制的适用范围超出了重复阶段博弈。
英文摘要：
While infinitely repeated games admit a rich set of Nash equilibria, finitely repeated games typically have a much smaller and often inefficient one. We show how to enlarge this set using deposits: in each period a player may place a refundable sum with a neutral intermediary, returned when the game ends and forfeited following a deviation. Paying these deposits is voluntary and incentive compatible at every stage, so no commitment by the players is assumed, the only commitment required being that of the intermediary to a refund rule fixed before play begins. The mechanism sustains payoff profiles more efficient than those of the standard equilibria, without altering the underlying game and without transfers between players. We demonstrate it on the prisoner's dilemma, a congestion game, and a public goods game, all settings where cooperation cannot emerge in the standard finitely repeated version. We also apply it to a dynamic common-pool resource, suggesting that the construction extends beyond repeated stage-games.
