Impartiality and interpersonal comparisons of variations in well-being

Abstract.The moral imperative requiring “equal treatment of equal claims,” or impartiality, is defined in the frameworks of Harsanyi's aggregation and impartial observer theorems as an axiomatic restriction of the underlying moral value judgments. The implications of impartiality for the functional form of the corresponding social welfare functions are derived and are shown to entail interpersonal comparison of variations in well-being. The argument is illustrated with examples.