Abstract

Should we remain neutral between our interests and those of future generations? Or are we ethically permitted or even required to depart from neutrality and engage in some measure of intergenerational discounting? This Article addresses the problem of intergenerational discounting by drawing on two different intellectual traditions: the social welfare function (“SWF”) tradition in welfare economics, and scholarship on “prioritarianism” in moral philosophy. Unlike utilitarians, prioritarians are sensitive to the distribution of well-being. They give greater weight to well-being changes affecting worse-off individuals. Prioritarianism can be captured, formally, through an SWF which sums a concave transformation of individual utility, rather than simply summing unweighted utilities in utilitarian fashion. The Article considers the appropriate structure of a prioritarian SWF in intergenerational cases. The simplest case involves a fixed and finite intertemporal population. In that case, I argue, policymakers can and should maintain full neutrality between present and future generations. No discount factor should be attached to the utility of future individuals. Neutrality becomes trickier when we depart from this simple case, meaning: (1) “non-identity” problems, where current choices change the identity of future individuals; (2) population-size variation, where current choices affect not merely the identity of future individuals, but the size of the world’s future population (this case raises the specter of what Derek Parfit terms “the repugnant conclusion,” i.e., that dramatic reductions in the average level of individual well-being might be compensated for by increases in population size); or (3) an infinite population. The Article grapples with the difficult question of outfitting a prioritarian SWF to handle non-identity problems, population-size variation, and infinite populations. It tentatively suggests that a measure of neutrality can be maintained even in these cases.