Axiomatizing Political Philosophy of Distributive Justice: Equivalence of No-envy and Egalitarian-equivalence with Welfare-egalitarianism

We characterize welfare-egalitarian mechanisms (that are decision-efficient and incentive compatible) with the two fundamental axioms of fairness: no-envy and egalitarian-equivalence. We consider cases where agents have equal rights over external world resources but are individually responsible for their preferences/costs. Our characterization answers the political philosophy question of what kind of welfare differentials allowed if we respect private ownership rights over self and public ownership over external world. We also relate no-envy and egalitarian-equivalence to "equality of what" debate and build a link between resource and opportunity egalitarianism, and welfare-egalitarianism.