From each According to his Ability, to each According to his Needs, or (even) more, if He Wishes

We show that Louis Blanc’s celebrated aphorism can be interpreted as a special case of the compensation principle, which has played a key role in the recent development of the axiomatic theory of resource allocation. We identify the most general model in which there is no conflict between efficiency and the principles of proportionality to ability and to needs. We also show the general compatibility between efficiency and the compensation principle, which generalizes Blanc’s principle of proportionality. We conclude on the necessity to bring the concept of heterogenous needs back into welfare economics.