A. Money-income compartsons (1) Comparison of changes over time in the composition of money incomes-or, more significantly, national products of different countries. (2) Comparison of the composition of money national products of different countries at the same time. B. Real-income comparisons (1) Comparison of changes in real income of different countries over time. (2) Comparison of real incomes of different countries at the same time.

Milton Gilbert, Colin Clark, J. R. N. Stone, Francois Perroux, D. K. Lieu, Evelpides, Francois Divisia, Tinbergen, Kuznets, Smithies, Shirras, MacGregor, The Measurement of National Wealth: Discussion, Econometrica, Vol. 17, Supplement: Report of the Washington Meeting (Jul., 1949), pp. 255-272