🤖 AI Summary
This study addresses the aggregation of individual preferences that incorporate altruistic or other-regarding concerns while respecting individual sovereignty. By introducing an individual sovereignty axiom and imposing two key requirements—sequential aggregation consistency and consensus stability—the authors demonstrate that social utility must be a linear combination of individuals’ self-interested utilities, with other-regarding concerns influencing only the weighting scheme. Moreover, the framework uniquely identifies the geometric mean as the rule for inter-individual weight allocation. Employing an axiomatic approach grounded in social choice theory, the analysis extends to settings with feasibility constraints and subjective uncertainty, thereby establishing both the structural role of other-regarding preferences and the uniqueness of the admissible weighting mechanism.
📝 Abstract
We consider the social aggregation of preferences over lotteries in the presence of other-regarding preferences. If society respects each individual's sovereignty, an axiom we propose akin to Sen's Liberalism, then society's utility is a linear combination of individuals' self-regarding utilities. That is, other-regarding preferences can only influence the weights society places on each individual. We next characterize the unique weighting method under which society's weight ratio between two individuals is the geometric mean of that of all individuals. The first distinguishing axiom concerns the consistency of sequential aggregation, while the second concerns consensus across changes in individuals' other-regarding preferences. We extend the first result to a setting with feasibility constraints and a setting with subjective uncertainty.