Social evaluation functionals: a gateway to continuity in social choice

This paper develops social choice theory aggregating individual utility functions to a social utility function. Such a tool allows me to deal with a natural notion of continuity in social choice theory. In addition, and in order to have the choice problem as close as possible to its beginnings, the social evaluation functionals considered are assumed to satisfy both ordinal measurability and interpersonal non-comparability, and unanimity. I present two results concerning the characterization of projective social evaluation functionals (which means that the social utility function is exactly the utility of the dictator). The first one needs a strong form of welfarism called social state separability. The second one uses continuity in combination with a new axiom called ordinal-scale-preserving. Copyright Springer-Verlag Berlin Heidelberg 2015