Dancing at gunpoint . A review of Herbert Gintis ’ s

Dancing at gunpoint. A review of Herbert Gintis's The bounds of reason: game theory and the unification of the behavioral sciences. The bounds of reason seeks to accomplish many things. It introduces epistemic game theory, discusses other-regarding preferences in games, offers an evolutionary model of property rights, and proposes a plan to unify the behavioural sciences. Most notably, it is a plea for the importance of human nature and sociality for the determination of strategic behaviour on the one hand, and a defence of traditional decision theory on the other. Being normatively predisposed by their nature, human players accept social norms as correlation devices that choreograph a correlated equilibrium. While social norms put on the dance, epistemic game theory is driven by the " cannons of rationality " (p. 83), as Gintis puts it in one of the many and sometimes hilarious misprints. Traditional decision theory is " mostly correct " (p. 246), and Gintis relies largely on its support for solving games. Thus the choreographer is restricted to where the cannons cannot reach. Game players are dancing at gunpoint here—with important consequences for the proposed unification of the behavioural sciences. But I am jumping ahead. The main part of The bounds of reason concerns a decision-theoretic approach to game theory. Its purpose is to investigate the (Bayesian) epistemic basis for central solution concepts, both as a justification of what is reasonable, as well as a derivational basis for predicting what is actually observed. This Bayesian rationality forms Gintis's " cannon of rationality " , which he aims at various game theoretic solution concepts. The first victim of this artillery is the assumption of common knowledge of rationality (CKR). Gintis argues that CKR is neither derivable from Bayesian rationality nor can it be epistemically justified on its own. It therefore cannot function as a premise of game theory, but must rather be interpreted as an " event " that may or may not occur