[Séminaire Caen] Comparisons for the Lesser Harm

Abstract:
We propose a new ordinal axiom to address the problem of interpersonal comparisons, which we call the Agreement Principle. The axiom says the following: if two individuals both agree that the worse-off person in one efficient allocation is better off than the worse-off person in another efficient allocation, then a social planner should prefer the first allocation. We show that any social preference satisfying this principle can be represented by what we call a Multi-Pareto-spined metric. In this representation, the welfare of each individual is given by the sum of two continuous and increasing indices. One index reflects that individual’s own preferences, and the other reflects the perspective of the other individual. For every Pareto-optimal allocation, these indices agree on how well each person is doing, ensuring consistency across the different viewpoints. We then explore the relationship between this representation and the concept of envy-freedom, and we identify conditions under which the two coincide. After presenting some illustrative examples, we conclude by discussing several possible extensions of the framework.
(joint with Y. Breitmoser)