On the informational basis of social choice

The notion of informational basis in social choice can be broadened so as to cover not only the standard notions related to interpersonal utility comparisons, but also information about utilities or preferences at (ir)relevant alternatives, non-utility features of alternatives, personal responsibility, unconcerned subpopulations, and feasibility constraints. This paper proposes a unified conceptual framework for all these notions, and analyzes the kind of information retained in each case. This new framework yields a deeper understanding of the difficulties and possibilities of social choice. New welfarism theorems are also obtained.