In defence[247] of his method of weighting, Fisher says, simply: "These weights are, of course, merely matters of opinion, but, as is well known, _wide differences in systems of weighting make only slight differences in the final averages_." (Italics mine.)[248]
Are these figures valid? Well, first one is struck with the absolute magnitude assigned to T. The figures seem vastly greater than would have been anticipated. The method of calculating it, for 1909, I shall discuss in detail in the chapter on "Statistical Demonstrations of the Quantity Theory." For the present, it is enough to note that the absolute magnitude is derived from figures collected by Dean David Kinley for the National Monetary Commission,[249] of deposits, exclusive of deposits made by one bank in another, made in about 12,000 banks (out of 25,000) on March 16, 1909. These deposits were classified as (1) money (with subdivisions) and (2) checks and other credit instruments. A cross-classification divided them into (1) retail deposits; (2) wholesale deposits; (3) all other deposits. Kinley's object was to determine the extent to which checks are used, as compared with money, in payments, particularly in wholesale and retail business. Fisher's total, briefly, was obtained as follows: Kinley's figures, for the one day, were increased to make an allowance for the non-reporting banks; they were further increased on the assumption that March 16 was below the average for the year; the figure finally obtained for the day was then multiplied by 303, assumed as the number of banking days in the year, and the product, 399 billions, was taken as representing the total circulation of money and checks in trade. For some reason not made clear, this total was subsequently reduced to 387 billions. Counting the average price, P, as $1, T was considered to be 387 billions.[250]
In the statistical chapter to follow, it will be shown that this estimate is a very decided exaggeration. Deposits made in banks greatly overcount trade. Very many payments represent duplications, loans and repayments, taxes, etc., and are in no sense trade. This is true of all classes of deposits, wholesale and retail, as well as "all other." But for the present, I am concerned with the question, not of the absolute magnitude of the volume of trade, but rather, the questions of its character, of the elements that enter into it, and, above all, of the extent to which it is physically determined by technical conditions of production, and the extent to which it is flexible, a matter of speculation, etc.