The inadequacy of Bayesian decision theory

Abstract

From the arguments presented in this paper I trust that we are in a position to see that Bayesian decision theory is inadequate both from the descriptive and normative standpoints. As a descriptive theory it is just false. As a normative theory we can say that there is a presumption in favour of the view that it is not irrational to value certainty as such (because this is in accord with ordinary intuition) and that no argument has been presented — and there seems little prospect of such an argument being presented — that would force us to abandon that presumption. That is, from the normative standpoint Bayesian decision theory is prima facie implausible. We have located the problem for Bayesianism in one of its rationality postulates, viz., the Sure-Thing Principle. Of course, this paper does not go very far in suggesting what is to supplant Bayesian decision theory as a theory of rational decision making. Nonetheless, I take the arguments in this paper to present a compelling reason for embarking on such a program.