The adequate consideration of the standard of living of a person or a family means establishing how much the unit of domestic consumption in question spends upon commodities during a particular economic period. It also means placing this amount in relation to the material requirements of life; in short, it means examining whether the quantity of commodities concerned is sufficient to fulfil the conditions necessary for an existence worthy of a human being, and whether it also leaves latitude for the satisfaction of cultural and luxury needs. Examination of the standard of living of a population whose individual members have different incomes means forming groups and working out the size of the components of this population that fall into each of the several categories that comprise a graded scale of living standards; the categories of this scale can be distinguished as poverty, indigence, sufficiency, affluence, and wealth. One must especially find out how the ‘bulk’ of the population (the half lying between the lower and upper quartiles) lives. The comparison of the standards of living of two populations — of two nations, of two social classes inside a nation, or of the same social classes in two different nations2 — would therefore involve examining how the two populations are divided between the categories of the scale of living standards.