Consider the alterative to expected utility model which incorporates measures of outcome utility relative to some prior expectation of what utility will be. Specifically, if outcome utility is below the expected level, then DM experiences disappointment; if the outcome utility is above the expected level, he experiences elation. The utility of a prosect X is then written: 72 (X) = p[u(x) + D(u(x) - prior)] i=1 Disappointment occurs when D(g) 0 if u(xi) - prior <0 w