Are Fleurbaey's and Roemer's theories of equal opportunity irreconcilable?

Summary The approach of equality of opportunity is becoming ubiquitous in the social justice literature. Marc Fleurbaey [1994], [2008] and John Roemer [1993], [1998] have played a major role in transmitting ideas put forth by philosophers and in transforming these ideas in models of social justice that can be absorbed by economists. The ideas of compensation and responsibility are defined in a different way by these two authors and we show that hybrid concepts are meaningful. More specifically, we propose a new principle of natural reward, ?reward on average,? which is compatible with the principle of compensation ex post in a quite general setting. Furthermore, we show how to introduce the idea of a social determinism in private choices in Fleurbaey?s approach.