Entropy control costs and entropic equilibria

Strategic errors may occur because of player trembles or because of noise in the communication channels. Suppose that the probability distribution of potential errors can be influenced at a cost γ proportional to the entropy reduction. This modified strategic-form game involves the choice of a probability distribution over strategies and a probability distribution over potential errors with weight ε on the latter. Each modified game has a Nash Equilibrium (NE), and any limit as ε → 0 is called an “γ-entropic equilibrium”, γ-entropic equilibria always exist and constitute a subset of trembling-hand-perfect equilibria, but otherwise γ-EE are independent of other refinements such as Proper NE.