Universal social orderings: An integrated theory of policy evaluation, inter-society comparisons, and interpersonal comparisons

We introduce the concept of a universal social ordering, defined on the set of pairs of an allocation and a preference profile of any finite population. It is meant to unify evaluations and comparisons of welfare (living standards) for individuals and populations of possibly different sizes and preferences. It can be used for policy evaluation, international comparisons, growth assessment, and inequality measurement. It even makes it possible to evaluate policy options that affect the size of the population or the preferences of its members.We study how to extend the theory of social choice in order to select such orderings on a rigorous axiomatic basis.We provide foundations for leximin as well as additively separable criteria. Key ingredients in this analysis are fairness principles in social aggregation, attitudes with respect to population size, and the bases of interpersonal comparisons.We discuss how this sheds light on recent developments in the empirical literature on international comparisons.