arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2005.10141cs.DCcs.GT
收藏

理性共识

Rational Consensus

Joseph Y. Halpern, Xavier Vilaca

摘要:

我们提供了一个博弈论分析的共识,假设过程是由理性的代理人控制,可能会失败的崩溃。我们认为代理\emph{care only about consensus}:也就是说,(a)代理的效用只取决于达成的共识值(而不是,例如,在代理发送的消息的数量)和(b)代理严格喜欢达成共识,不达成共识。我们表明,在这些假设下,没有\emph{ex post Nash Equilibrium},即使只有一个故障。粗略地说,这意味着必须始终存在一个\emph{failure pattern}(描述谁失败,何时失败,以及在失败的回合中不向哪些代理发送消息)和代理可以通过偏离获得的初始首选项。另一方面,如果我们假设故障模式和初始偏好存在分布$π$,则在对$π$的最小假设下,存在容忍$f$故障的纳什均衡(即,如果是$f+1 < n$(其中$n$是座席总数),则$π$将概率1设置为最多存在$f$故障。此外,我们表明,轻微的扩展的纳什均衡策略也是一个\emph{sequential}均衡(在相同的假设下的分布$π$)。

英文摘要:

We provide a game-theoretic analysis of consensus, assuming that processes are controlled by rational agents and may fail by crashing. We consider agents that \emph{care only about consensus}: that is, (a) an agent's utility depends only on the consensus value achieved (and not, for example, on the number of messages the agent sends) and (b) agents strictly prefer reaching consensus to not reaching consensus. We show that, under these assumptions, there is no \emph{ex post Nash Equilibrium}, even with only one failure. Roughly speaking, this means that there must always exist a \emph{failure pattern} (a description of who fails, when they fail, and which agents they do not send messages to in the round that they fail) and initial preferences for which an agent can gain by deviating. On the other hand, if we assume that there is a distribution $π$ on the failure patterns and initial preferences, then under minimal assumptions on $π$, there is a Nash equilibrium that tolerates $f$ failures (i.e., $π$ puts probability 1 on there being at most $f$ failures) if $f+1 < n$ (where $n$ is the total number of agents). Moreover, we show that a slight extension of the Nash equilibrium strategy is also a \emph{sequential} equilibrium (under the same assumptions about the distribution $π$).

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑