An Inequality Measure for Stochastic Allocations

Abstract

Few papers in the literature on inequality measurement deal with uncertainty, particularly when the ranking of cohorts may not be fixed. We present a set of axioms implying such a class of inequality measures under uncertainty that is a one-parameter extension of the generalized Gini mean over the distribution of average allocations. The extension consists of a quadratic term accounting for inter-personal correlations. In particular, our measure can simultaneously accommodate a preference for "shared destiny", a preference for probabilistic mixtures over unfair allocations, and a preference for fairness "for sure" over fairness in expectation.