Formal Decision Theory and Majority Rule

Abstract

In a paper entitled "Beyond the Voter's Paradox" (Ethics, October 1977), I outlined a general theory of rationality for social decision procedures according to which rationality consists in procedural determinacy, a condition in which the aggregated desiderative data wholly entail the decision drawn from them, and irrationality consists in procedural indeterminacy, a condition which makes possible the Voter's Paradox and the various other deficiencies of existing voting practices. I also argued that, with a minor modification, C. L. Dodgson's Method of Marks would conform to this criterion of rationality, and, further, that use of this Modified Method of Marks in practice would have the effect of eliminating many cumbersome features of majority rule. In a response to this paper, Elaine Mates Spitz claims, not only that there are defects in the Modified Method of Marks, but also that all formal models of decision theory fail to reflect fully the political, social, and moral complexities of majority rule, and therefore have no place either in justifying or attacking it (Elaine Mates Spitz, "Majority Rule: The Virtue of Numbers," Ethics, vol. 89, no. 1 [October 1978]). My main concern in this paper will be to defend the use of such formal models against this sort of attack. However, because it is made to appear that the attack draws much of its force from its seemingly devastating criticisms of the Modified Method of Marks, I will begin by correcting the distortions of this method which make that sham seem plausible.