Introduction

Economists accept the idea that a person can have a coherent ordering over the states of the world; yet it is commonplace to balk at the notion that there exists a coherent interpersonal ordering, which would give sense to statements of the form 'person i is better off in state x than person j is in state y.′ The reason for such skepticism is that whereas in the first case one mind is making judgments about states of the world, there is no universal mind that can make interpersonal judgments. Nevertheless, most of us feel capable of making some interpersonal comparisons, perhaps by virtue of the limited empathy we feel, because we believe at some level all people are relevantly similar. We will argue that it may be quite reasonable to suppose the existence of an interpersonal ordering of the states of the world, based on a kind of empathy that a person can legitimately feel, because he has, during his life, indeed been a person of various different types.

Interpersonally comparable utility has had a checkered history. In the nineteenth century (see Cooter and Rappoport (1986)), the possibility of interpersonal comparisons was taken for granted by many social theorists. The ordinalist revolution dissolved this innocent presumption; its supporters claimed that interpersonal comparisons were necessarily normative, hence not within the purview of positive economics (see also Sen (1979) for a discussion). There are, it seems, two different bases for the current agnosticism, or rather nihilism, with respect to the existence of an interpersonal ordering.