Abstract: Can we make interpersonal comparisons of well-being? The nature of the problem of interpersonal comparison changes as the account of well-being that one adopts changes, and our question is, are interpersonal comparisons of well-being possible on the best account of well-being, viz. the informed-desire account with a high standard for ‘informed’. After discussing John Harsanyi's idea of an extended utility function and the idea of a deep monistic utility function, the chapter concludes that, as the informed-desire account gives us something approaching an objective list of elements of well-being, the terms in which we speak quantitatively about one person's well-being are not relative to other things that this individual wants but relative to quantitative assessment of other people's well-being. There is, therefore, no gap between assessments of different persons’ well-being that needs bridging. The chapter concludes with discussions of intra-personal, inter-temporal comparisons and of comparisons on a large social scale.

Keywords: John Harsanyi, inter-personal comparison, intra-personal comparisons, well-being,