ON NATURAL AND MARKET PRICE
IN making labour the foundation of the value of commodities, and the comparative quantity of labour which is necessary to their production, the rule which determines the respective quantities of goods which shall be given in exchange for each other, we must not be supposed to deny the accidental and temporary deviations of the actual or market price of commodities from this, their primary and natural price.
In the ordinary course of events, there is no commodity which continues for any length of time to be supplied precisely in that degree of abundance which the wants and wishes of mankind require, and therefore there is none which is not subject to accidental and temporary variations of price.
It is only in consequence of such variations that capital is apportioned precisely, in the requisite abundance and no more, to the production of the different commodities which happen to be in demand. With the rise or fall of price, profits are elevated above, or depressed below, their general level; and capital is either encouraged to enter into, or is warned to depart from, the particular employment in which the variation has taken place.
Whilst every man is free to employ his capital where he pleases, he will naturally seek for it that employment which is most advantageous; he will naturally be dissatisfied with a profit of 10 per cent., if by removing his capital he can obtain a profit of 15 per cent. This restless desire on the part of all the employers of stock to quit a less profitable for a more advantageous business has a strong tendency to equalise the rate of profits of all, or to fix them in such proportions as may, in the estimation of the parties, compensate for any advantage which one may have, or may appear to have, over the other. It is perhaps very difficult to trace the steps by which this change is effected: it is probably effected by a manufacturer not absolutely changing his employment, but only lessening the quantity of capital he has in that employment. In all rich countries