ON THE INFLUENCE OF DEMAND AND SUPPLY ON PRICES
IT is the cost of production which must ultimately regulate the price of commodities, and not, as has been often said, the proportion between the supply and demand: the proportion between supply and demand may, indeed, for a time, affect the market value of a commodity, until it is supplied in greater or less abundance, according as the demand may have increased or diminished; but this effect will be only of temporary duration.
Diminish the cost of production of hats, and their price will ultimately fall to their new natural price, although the demand should be doubled, trebled, or quadrupled. Diminish the cost of subsistence of men, by diminishing the natural price of the food and clothing by which life is sustained, and wages will ultimately fall, notwithstanding that the demand for labourers may very greatly increase.
The opinion that the price of commodities depends solely on the proportion of supply to demand, or demand to supply, has become almost an axiom in political economy, and has been the source of much error in that science. It is this opinion which has made Mr. Buchanan maintain that wages are not influenced by a rise or fall in the price of provisions, but solely by the demand and supply of labour; and that a tax on the wages of labour would not raise wages, because it would not alter the proportion of the demand of labourers to the supply.
The demand for a commodity cannot be said to increase if no additional quantity of it be purchased or consumed; and yet under such circumstances its money value may rise. Thus, if the value of money were to fall, the price of every commodity would rise, for each of the competitors would be willing to spend more money than before on its purchase; but though its price rose 10 or 20 per cent., if no more were bought than before, it would not, I apprehend, be admissible to say that the variation in the price of the commodity was caused by the increased demand for it. Its natural price, its money cost of production,