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：在诸如"胆小鬼博弈"这类混合动机协调问题中，智能体可能无法在帕累托有效结果上达成协调。安全帕累托改进最初被提出用于缓解以下情况下的协调失败：参与者对其委托方如何执行博弈缺乏概率信念；通过指令使委托方的行为确保相对于默认执行方式获得帕累托改进。更一般地，SPI可定义为策略剖面的变换，使得所有参与者在变换后的剖面下必然获得更优结果。本文研究了SPI能在多大程度上减少期望效用最大化智能体间协调失败带来的负面影响。我们考察参与者提交可依据彼此代码条件执行决策的计算机程序的博弈，并利用该特性通过具备再协商能力的程序构建SPI。首先证明在参与者信念的温和条件下，每个参与者始终倾向于采用再协商机制。继而证明在类似假设下，每个参与者至少愿意再协商至获得其在任何有效结果中可能取得的最低收益。因此主观最优博弈能确保参与者至少获得这些收益，而无需就特定帕累托改进达成协调。最后证明再协商机制无法保证参与者在此界限上获得进一步改进。