PRIORITY, SOLIDARITY AND EGALITARIANISM

Using the axioms of “priority" and “solidarity" (sol-idarity in the influences on the original members of the changes in population or resources) in a variable and potentially infinite population model, Moreno-Ternero and Roemer (2006) establish an axiomatic characterization of index-egalitarian rules. We show that the same characterization result can be established in a fixed and finite population model, when their solidarity is replaced with the axiom of agreement. This axiom requires that when there is a change in agents' characteristics (output functions) or total re-sources, all agents who remain unchanged should be influenced in the same direction; all unchanged agents get more, all get less, or all get the same amount as before. We also show that agreement can be replaced with the combination of resource monotonicity and separability and that the priority axiom in Moreno-Ternero and Roemer (2006) can be replaced with some alternative formal-izations of Parfit’s priority view.