Assessing risky social situations

This paper re-examines the welfare economics of risk. It singles out a class of criteria, the “expected equally-distributed equivalent”, as the unique class which avoids serious drawbacks of existing approaches. Such criteria behave like ex-post criteria when the final statistical distribution of wellbeing is known ex ante, and like ex-ante criteria when risk generates no inequality. The paper also provides a new result on the tension between inequality aversion and respect of individual ex ante preferences, in the vein of Harsanyi’s aggregation theorem.