Impartiality, priority, and solidarity in the theory of justice

The ethic of 'priority' is a compromise between the extremely compensatory ethic of 'welfare equality' and the needs-blind ethic of 'income equality'. We propose an axiom of priority, and characterize resource-allocation rules that are impartial, prioritarian, and solidaristic. They comprise a class of rules which equalize across individuals some index of resources and welfare. Consequently, we provide an ethical rationalization for the many applications in which such indices have been used (e.g., the 'human development index,' 'index of primary goods,' etc.)