Probability adjusted rank-discounted utilitarianism

Abstract

Probability adjusted rank-discounted critical-level generalized utilitarianism (PARDCLU) provides a formal framework for social evaluation that accommodates both variable population sizes and risky outcomes. By generalizing rank-discounted utilitarianism, this approach facilitates the assessment of long-run policies, such as climate change mitigation, where consequences are both distant and uncertain. The criterion is characterized by an axiomatic foundation that includes probability-adjusted Suppes-Sen and existence independence principles. Unlike traditional discounted utilitarianism, which prioritizes generations based on their chronological position, PARDCLU assigns weights based on relative well-being levels, thereby ensuring intergenerational equity. This structure effectively avoids both the Repugnant Conclusion and the Very Sadistic Conclusion, providing a robust normative basis for population ethics. In specific applications, PARDCLU yields rank-dependent expected utilitarianism and incorporates the probability of human extinction into the social welfare order. The methodology further addresses practical implementation issues, including the duration of the planning horizon, the maintenance of time consistency, and the tensions between ex ante and ex post social choice perspectives. – AI-generated abstract.