Some Comments

Elmer Working called in 1927 the attention of economists to some facts well known in their substance to the price-theory but sometimes neglected in the statistical work. He stressed the fact that the mere existence of a statistical series of different prices and quantities of a commodity sold in the market does not exclude changes of demand and supply curves. If neither of these curves remains stable, then a curve ‘fitted’ statistically to the ‘scatter-diagram’ of the market necessarily reflects not only the shapes of the demand and supply curves but also the kind of fluctuations they underwent during the observation period. Accordingly, H. Schultz and H. L. Moore, in their well-known works, tried to eliminate at least a part of the time-change by assuming a ‘routine of change’ – of demand only. J. Tinbergen preferred to eliminate, not the time, which is of course in itself not an economic cause, but a few definite factors supposed to be pertinent to supply and demand shifts of the particular commodity considered. W. Leontief attempted to derive a method of eliminating time-shifts, starting from the assumption that they must have an erratic character.

Now, R. Frisch introduced notions which enabled him to develop analytically E. Working's statements. By applying these notions to Leontief's methods he succeeded in giving to this method an elementary mathematical exposition which is considerably simpler and at the same time more general than the exposition given originally by W. Leontief and his mathematical collaborator, R. Schmidt.