We confront two common objections to Harsanyi's impartial observer theorem; one to do with 'fairness', and the other to do with different individuals' having different attitudes toward risk. Both these objections can be accommodated if we drop the reduction axiom; in particular, if we...

Empirical evaluation of policies to mitigate climate change has been largely confined to the application of discounted utilitarianism (DU). DU is controversial, both due to the conditions through which it is justified and due to its consequences for climate policies, where the discounting of...

Koopmans’s (Econometrica 28, 287–309) axiomatization of discounted utilitarianism is based on seemingly compelling conditions, yet this criterion leads to hard-to-justify outcomes. The present analysis considers a class of sustainable recursive social welfare functions within Koopmans’s...