Interpersonal Comparisons of What?

Jean Baccelli (University of Pittsburgh)

Abstract:  A fundamental question of social choice theory is whether collective decision-making requires interpersonal comparisons of welfare. Arrow's and Sen's pioneering contributions to this field have long been interpreted as confirming that such is the case. It is now held that a more nuanced answer is in order. Social choice theorists highlight the possibilities illustrated by, e.g., the Borda count or Nash's bargaining solution, that do not seem to assume any interpersonal comparability. I will examine whether these two famous examples do, as claimed, eschew interpersonal comparisons. I will show that, in different ways, they do not. I will discuss the implications for social choice theory and the philosophy of economics.