Rationality and Knavery

Abstract

This paper makes a modest point. Suppose one wants to evaluate alternative policies, institutions or even constitutions on the basis of their consequences. To do so, one needs to evaluate their consequences and one needs to know what their consequences are. Let us suppose that the role of economic theories and game theory in particular is mainly to help us to use information we already possess or that we can acquire at a reasonable cost to judge what the consequences will be. We do not necessarily need true theories or theories that provide perfectly precise predictions. What sort of accuracy and precision we need depends on how the consequences of alternative policies are evaluated. The worth of an economic theory in this context of policy assessment depends on the accuracy of the predictions the theory permits, the costs of gathering the needed information, and the costs of learning and using the theory. My only excuse for uttering these truisms is that well known economists and philosophers have denied them.

I am grateful for criticisms from Jeffrey Johnson, Julian LeGrand, and audiences at the University of Wisconsin, Duke University, the University of Exeter, and the Conference on Game Theory, Experience, and Rationality sponsored by the Institute Vienna Circle.