The allocation of resources so as to yield the maximum effect was rightly recognized as one of the most vital and difficult of our war-time problems. To cope with it, the Allied peoples devised one instrument after another, and finally evolved the Supreme Allied Council. The analogous problem in the economic world of peace time is no less important and far more difficult; but there is nothing to correspond to the Supreme Allied Council. There we rely upon a co-operation which, as was stressed in Chapter I, is unco-ordinated. That co-operation has been evolved by the mutual competition of innumerable business concerns, controlled by men largely animated by the motive of pecuniary profit. But it has not been evolved wholly by such means: and how far that competition or that motive of profit is essential to its efficiency are questions with which this volume has not been in any way concerned. The economic laws, the relations between utility, and price and cost, with which it has been occupied, are an entirely different matter; and these _are_ essential to the efficiency of any system of society. For if the marginal utility of a commodity is equal to its marginal cost, and if this marginal cost is composed of payments to the various agents of production at least as great as they could have obtained if they had been used otherwise, this amounts to saying that the agents of production are so utilized as to yield the maximum utility; and this is the same thing as saying that they are so utilized as to produce the maximum wealth.