We consider a simple production model and we assume that agents have unequa
l production skills which can in no way be attributed to their responsibili
ty. We study how it is possible, if at all, to compensate for differential
skills by applying Rawls's idea of a collective sharing in the benefits of
skills. For this purpose, we introduce an axiom of solidarity, according to
which agents should all be affected in the same direction if the profile o
f personal skills changes. We show that particular allocation rules are cha
racterized be combining this axiom with a requirement of non-discrimination
among preferences, or with a property capturing Nozick's idea of guarantee
ing a minimal benefit from one's own skill.