Agents in mixed-motive coordination problems such as Chicken may fail to coordinate on a Pareto-efficient outcome. Safe Pareto improvements (SPIs) were originally proposed to mitigate miscoordination in cases where players lack probabilistic beliefs as to how their delegates will play a game; delegates are instructed to behave so as to guarantee a Pareto improvement on how they would play by default. More generally, SPIs may be defined as transformations of strategy profiles such that all players are necessarily better off under the transformed profile. In this work, we investigate the extent to which SPIs can reduce downsides of miscoordination between expected utility-maximizing agents. We consider games in which players submit computer programs that can condition their decisions on each other's code, and use this property to construct SPIs using programs capable of renegotiation. We first show that under mild conditions on players' beliefs, each player always prefers to use renegotiation. Next, we show that under similar assumptions, each player always prefers to be willing to renegotiate at least to the point at which they receive the lowest payoff they can attain in any efficient outcome. Thus subjectively optimal play guarantees players at least these payoffs, without the need for coordination on specific Pareto improvements. Lastly, we prove that renegotiation does not guarantee players any improvements on this bound.

翻译：混合动机协调问题（如“懦夫博弈”）中的智能体可能无法协调达成帕累托最优结果。安全帕累托改进（SPI）最初旨在缓解玩家缺乏代理人策略概率信念时的协调失败情况——代理人被指示以确保默认策略获得帕累托改进的方式行事。更一般地，SPI可定义为策略配置的变换，使得所有玩家在新配置下的收益必然优于原配置。本文探究SPI能在多大程度上降低期望效用最大化主体间协调失败的风险。我们考虑玩家提交计算机程序的博弈场景，这些程序能根据对手代码调整决策，并利用这一特性通过具备重新谈判能力的程序构建SPI。首先证明在玩家信念的温和条件下，每个玩家始终偏好采用重新谈判策略。其次表明在类似假设下，每个玩家至少愿意重新谈判至其所能获得的最低收益（该收益出现在任意帕累托有效结果中）。因此，主观最优玩法能保证玩家获得不低于此阈值的收益，而无需协调具体的帕累托改进方案。最后证明重新谈判无法为玩家带来超越该界限的任何改进。