One difficulty this approach faces is to clarify the basis for holding people responsible for their choices and the extent to which people will be held responsible for the effects of their choices that fall on themselves. John Roemer has developed a framework for addressing this difficulty. His idea is one that societies with different notions of how much responsibility for choice to assign to individuals could use to determine what equal opportunity would require given their favored notion of individual responsibility (Roemer 2002 and 2003; for criticism, see Risse 2002 and Hurley 2003).