Any procedure of social choice makes use of some types of information and ignores others. For example, the method of majority decision concentrates on people's votes, but pays no direct attention to, say, their social standings, or their prosperity or penury, or even the intensities of their...

In this paper, we study intertemporal social welfare evaluations when agents have heterogeneous preferences that are interpersonally noncomparable. We first show that even if all agents share the same preferences, there is a conflict between the axioms of Pareto principle, time consistency, and...