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arXiv · 2501.05481

Blackwell Equilibrium in Repeated Games

Costas Cavounidis·Sambuddha Ghosh·Johannes Hörner·Eilon Solan·Satoru Takahashi
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Abstract

We apply Blackwell optimality to repeated games. An equilibrium whose strategy profile is sequentially rational for all high enough discount factors simultaneously is a Blackwell (subgame-perfect, perfect public, etc.) equilibrium. The bite of this requirement depends on the monitoring structure. Under perfect monitoring, a ``folk'' theorem holds relative to an appropriate notion of minmax. Under imperfect public monitoring, absent a public randomization device, any perfect public equilibrium generically involves pure action profiles or stage-game Nash equilibria only. Under private conditionally independent monitoring, in a class of games that includes the prisoner's dilemma, the stage-game Nash equilibrium is played in every round.

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Costas Cavounidis, Sambuddha Ghosh, Johannes Hörner, Eilon Solan, Satoru Takahashi. 2025-01-07. Blackwell Equilibrium in Repeated Games. https://arxiv.org/abs/2501.05481

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