Social Preference Ordering in a Probabilistic Voting Model

In: Public choice, Band 24, S. 93-100

Abstract

The purpose is to suggest the advantages of a probabilistic model of social choice in which some naive assumptions on the individual preference relations are imposed. According to the probabilistic approach, society chooses a certain alternative in a 2-state process:(1) social probabilities are determined on the basis of individual probabilities using the X rule, & (2) a certain alternative is chosen by a random mechanism which utilizes the above social probabilities. The proposed social decision rule is of great advantage in that it satisfies a list of properties which seem desirable in a democratic political system. In particular, this rule satisfies 4 of the conditions introduced by K. Arrow (SOCIAL CHOICE AND INDIVIDUAL VALUES, New York, NY: John Wiley, 1951); it takes into account all individual preferences, including those of the minority, & intensity of preferences. The social preference ordering generated by this rule is reflexive, complete, & transitive. In this sense social rationality exists. By making some simplified assumptions on voters preferences it is shown how democratic voting can be organized & the best social choice achieved on the basis of relatively modest information, the source of which must be, of course, the voters themselves. AA.