An axiomatic basis for distributional equality in utilitarianism

An axiomatic basis for a social preference ordering with interval-scaled utility levels satisfying the principles of anonymity and pareto superiority is elaborated. The ordering is required to be sensitive to distributional equality: Redistribution of utility income from poor to rich persons without changing their social rank should lead to a superior evaluation. The axiom of separability is weakened in order to make it compatible with distributional equality. We prove that every continuous ordering satisfying the upper axioms can be represented by a utility function which is positively linear on the convex cone of rank-ordered utility vectors. A modified unnormalized Gini coefficient is one possible choice, but it contradicts, as well as related proposals, the principle of adequacy of means for some distribution problems.