Best Fit Social Choices: An Alternative to Arrow

Abstract

This paper explores an approach to social choice which is an alternative to Arrow's social welfare function. We consider 'best fit' social rankings for any individual preferences through the definition of levels of agreement between preferences and rankings. We thereby avoid the pairwise approach of Arrow's independence and Pareto conditions, and we demonstrate the possibility of non-dictatorial social choice. Mie consider the rationality implications of a non-unique outcome, and determine additional properties, including majority-consistency, of the Condorcet process for determining the rankings. The approach also allows an interpretation of Sen's 'impossibility of a Paretian liberal' in terms of individual agreement.