A Risky Problem for Permutation Invariance

According to the principle of Permutation Invariance, the ethical comparison of welfare distributions should be unchanged by permutations on the set of individuals—including infinitary permutations, if the population is infinite. This paper highlights a problem for Permutation Invariance involving risky prospects, improving upon a related result due to Jonsson and Peterson (2020). It is shown that, given plausible auxiliary assumptions, proponents of Permutation Invariance must reject either a weak ex ante Pareto principle or the decision-theoretic axiom of negative dominance (introduced by Lederman, forthcoming).