Page:Walter Renton Ingalls - Current Economic Affairs (1924).pdf/106

92 The data for consumption are based on the reports of the U. S. Geological Survey, the U. S. Department of Agriculture, the American Iron and Steel Institute and the American Bureau of Metal Statistics. Such of the data as was originally expressed in terms of bales, bushels, barrels, thousands, etc., have been converted into terms of weight by the use of well known factors in order to have a uniform expression in pounds. Wherever the authorities cited have computed consumption their figures for it have been used. Where no such computations have been made I have done them myself, adding production and imports and deducting exports. Wherever there have been data for stocks, allowance for changes in them, plus or minus, between the beginning and end of the years, has been made. This is the conventional statistical method of computing consumption, but in reality it gives deliveries for consumption rather than actual consumption. However, the differences between those two heads are probably immaterial in the present consideration.

In some instances, such as stone, clay and a few other rough commodities for which only production figures are available the same have been taken as equivalent to consumption, which doubtless is near enough. I have divided the consumption in each year of the two triennial periods by the population at the middle of the year and have computed the arithmetical average of the quotients. In considering the data in the accompanying table some allowance must be made for error in the original statistics, but with respect to all of the principal commodities such errors as there may be are surely immaterial.