Utilitarian Collective Choice and Voting

Published: Dec. 1, 2004, 11 a.m.

b'In his seminal Social Choice and Individual Values, Kenneth Arrow stated that his theory applies to voting. Many voting theorists have been convinced that, on account of Arrow\\u2019s theorem, all voting methods must be seriously flawed. Arrow\\u2019s theory is strictly ordinal, the cardinal aggregation of preferences being explicitly rejected. In this paper I point out that all voting methods are cardinal and therefore outside the reach of Arrow\\u2019s result.\\n\\tParallel to Arrow\\u2019s ordinal approach, there evolved a consistent cardinal theory of collective choice. This theory, most prominently associated with the work of Harsanyi, continued the older utilitarian tradition in a more formal style. The purpose of this paper is to show that various derivations of utilitarian SWFs can also be used to derive utilitarian voting (UV). By this I mean a voting rule that allows the voter to score each alternative in accordance with a given scale. UV-k indicates a scale with k distinct values. The general theory leaves k to be determined on pragmatic grounds. A (1,0) scale gives approval voting. I prefer the scale (1,0,-1) and refer to the resulting voting rule as evaluative voting.\\n\\tA conclusion of the paper is that the defects of conventional voting methods result not from Arrow\\u2019s theorem, but rather from restrictions imposed on voters\\u2019 expression of their preferences.\\n\\tThe analysis is extended to strategic voting, utilizing a novel set of assumptions regarding voter behavior.'