Before revision: We introduce empirical equilibrium, a refinement of Nash equilibrium . In contrast to previous refinements in the literature, empirical equilibrium is based solely on observables and does not determine as implausible all weakly dominated behavior. We show that a distribution of play is an empirical equilibrium if and only if it is the limit of regular Quantal Response Equilibria associated with quantal responses that are utility maximizing in the limit. This result provides a direct link between the practice of experimental economics and our refinement .
After revision: We introduce empirical equilibrium, a refinement of Nash equilibrium that is based on a non-parametric characterization of empirical distributions of behavior in games (Velez and Brown,2020b arXiv:1907.12408). The refinement can be alternatively defined as those Nash equilibria that do not refute the regular QRE theory of Goeree, Holt, and Palfrey (2005). By contrast, some empirical equilibria may refute monotone additive randomly disturbed payoff models. As a by product, we show that empirical equilibrium does not coincide with refinements based on approximation by monotone additive randomly disturbed payoff models, and further our understanding of the empirical content of these models .