The primary-goods indexation problem in Rawls's theory of justice

Rawls's Difference Principle holds that basic social institutions are just if they maximize the worst-off individual's potential welfare, which depends on the vector of amounts of primary goods. As Rawls recognized, the multiplicity of primary goods poses an index number problem. This paper uses the machinery of social choice to characterize the class of procedures for aggregating quantities of several primary goods into a composite ordinal index that are consistent with Rawls's analysis. Only very simple and unattractive aggregation methods in which the various primary goods play roles of radically different magnitudes are compatible with Rawls's argument.