it consists of money, "not but
The crudest and most popular conception of income is that it consists of money, "not necessarily coins, but either coin or some kind of written or printed order which enables " people " to receive coin if they want it. "1 But it is necessary to draw aside the veil, which the habitual use of money throws over most economic processes, and to consider not merely money but money's worth, not merely money income but real income, in the shape of those things which are bought with money income. For the purpose of my subsequent argument a person's real income during a given period should be so defined, as to correspond as closely as possible with the means of economic welfare which become available 'to him during this period. Any person's real income contains many heterogeneous elements, various sorts of food amd clothes, house room of varying quantity and quality, various personal services and so forth. In order, therefore, to compare the size of two or more real incomes, it is necessary to express all these elements in terms of some one common measure. The most obvious common measure is money value, which can in practice be used with approximate accuracy, corrections being made for variations, as between different times, places, and social
groups, in the purchasing power of money. We thus seem to return, in substance, to the original conception of money income. But it is important to notice that money income, as commonly conceived, is not equivalent tu the money value of real income, as it is here convenient to define the latter. For, on the one hand, there are certain elements of money income, to which no elements of real income correspond ; and, on the other hand, there are certain elements of real income, to which no elements of money income correspond.