Abstract Correlated equilibrium constitutes one of the basic solution concepts for static games with complete information. Actually two variants of correlated equilibrium are in circulation and have been used interchangeably in the literature. Besides the original notion due to Aumann (1974), there exists a simplified definition typically called canonical correlated equilibrium or correlated equilibrium distribution. It is known that the original and the canonical version of correlated equilibrium are equivalent from an ex-ante perspective. However, we show that they are actually distinct – both doxastically as well as behaviourally – from an interim perspective. An elucidation of this difference emerges in the reasoning realm: while Aumann’s correlated equilibrium can be epistemically characterized by common belief in rationality and a common prior, canonical correlated equilibrium additionally requires the condition of one-theory-per-choice. Consequently, the application of correlated equilibrium requires a careful choice of the appropriate variant.

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相关均衡的两个定义

摘要 相关均衡构成了完全信息静态博弈的基本解概念之一。实际上，相关均衡的两种变体正在流通，并且在文献中可以互换使用。除了 Aumann (1974) 提出的原始概念外，还有一个简化的定义，通常称为典型相关均衡或相关均衡分布。众所周知，从事前的角度来看，相关均衡的原始版本和规范版本是等价的。然而，我们表明，从临时的角度来看，它们实际上是不同的——无论是在信仰上还是在行为上。在推理领域中出现了对这种差异的阐明：虽然奥曼的相关均衡可以通过对理性的共同信念和共同的先验在认识上表征，但规范相关均衡还需要每个选择一个理论的条件。因此，相关均衡的应用需要仔细选择适当的变体。