How to Make Sense of Game Theory

Abstract

The paper examines the extent to which game theory can be derived from a strictly Bayesian or decision theoretic point of view, since this is the only way to gain a unified theory of practical rationality. It observes that no such derivation exists and criticizes the standard arguments for the rationality of equilibrium strategies in two-person zero-sum games. It then proposes the beginnings of the theory or rationalizability (as it has been called later on) and observes its restrictions. It continues with pleading for a strict distinction of action rationality and epistemic rationality (which are confounded in game theory). The final critical discussion of Harsanyi's stance concludes that issues of epistemic rationality are independent and need to be explicitly considered in game theory and proposes to explain the subjective probabilities of the players, as they are assumed in game theory, as evolving in Bayesian game learning processes. (The postscript of the German version adds some comparative remarks on Skyrms' theory of practical deliberation.) [