 The SWFL approach has been generalized to the case in which each individual has multiple welfare functions (e.g., a \(k\)-tuple of them), capturing (i) multiple opinions about each individual’s welfare (e.g., Roberts 1995; Ooghe and Lauwers 2005) or (ii) multiple dimensions of welfare (e.g., List 2004a). In this case, we are faced not only with issues of measurability and interpersonal comparability, but also with issues of inter-opinion or inter-dimensional comparability. To obtain compelling possibility results, comparability across both individuals and dimensions/opinions is needed. A related literature addresses multidimensional inequality measurement (for an introductory review, see Weymark 2006).