Impartial utilitarianism on infinite utility streams

TL;DR

This paper axiomatizes impartial utilitarian rules for evaluating infinite utility streams, emphasizing long-term fairness and connecting to Banach limits, thus advancing intergenerational policy evaluation.

Contribution

It provides axiomatic characterizations of impartial utilitarian rules over infinite streams, linking them to Banach limits and extending the theoretical foundation for intergenerational fairness.

Findings

Characterization of social welfare orderings by long-run averages.

Necessary and sufficient conditions for bounded streams.

Connection of axioms to Banach limits.

Abstract

When evaluating policies that affect future generations, the most commonly used criterion is the discounted utilitarian rule. However, in terms of intergenerational fairness, it is difficult to justify prioritizing the current generation over future generations. This paper axiomatically examines impartial utilitarian rules over infinite-dimensional utility streams. We provide simple characterizations of the social welfare ordering evaluating utility streams by their long-run average in the domain where the average can be defined. Furthermore, we derive the necessary and sufficient conditions of the same axioms in a more general domain, the set of bounded streams. Some of these results are closely related to the Banach limits, a well-known generalization of the classical limit concept for streams. Thus, this paper can be seen as proposing an appealing subclass of the Banach limits by the axiomatic analysis.