An attempt to deal with individual welfare functions seems appropriate in this volume. As early as 1951, Arrow summarized some other scholars’ views on individual welfare functions (Arrow 1951, p. 5). In contrast with Arrow’s pathbreaking theoretical work, this chapter will deal with some attempts to empirically specify individual welfare functions. These attempts are close to Levy and Guttman (1975) (which mentions Guttman’s previous work (1971)), and to van Praag (1971), which was followed by an impressive quantity of further empirical work by himself and his pupils.