# Ex ante versus ex post equality of opportunity

###### Working Paper 2009-141

Abstract

We study the difference between the ex post and the ex ante perspectives in equality of opportunity (EOp), and the possibility of a clash between them. We argue that ex ante EOp is a potential trap because someone motivated by ex post EOp may be led to believe that ex ante EOp is another natural embodiment of the same idea. As we show, it is not. Moreover, we explore the relationship between the ex post/ex ante tension and the well documented clash between the "compensation principle" and various "reward principles": we show that the tension between reward and compensation only exists if one endorses an ex post view of EOp; on the contrary, it vanishes if one adopts an ex ante view of equality of opportunity.

Authors: Marc Fleurbaey, Vito Peragine.

Keywords: equality of opportunity, ex ante/ex post, compensation, reward
JEL: D63, D71.