Sen (1970a) proposes a further generalization of the social choice framework, by permitting consideration of information about individual utility functions, not only preferences. This enlargement is motivated by the impossibility theorem, but also by the ethical relevance of various kinds of data. Distributional issues obviously require interpersonal comparisons of well-being. For instance, an egalitarian evaluation of allocations needs a determination of who the worst-off are. It is tempting to