We examine the possibilities of extending Sen's taxonomy of fixed-population information assumptions regarding the measurability and interpersonal comparability of individual utilities to social-choice problems where the population may very.

This paper proposes a definition of uncertainty aversion for nonprobabilistic decision models and characterizes the decision rules that are uncertainty averses in that sense. Dual results are obtained for uncertainty appeal and it is shown that imposing an uncertainty neutrality condition leads...

This paper analyses a two-period foreign-aid model where assistance can be given in the form of consumption or population control aid.