The quantity of every commodity brought to market naturally suits itself to the effectual demand. It is the interest of all those who employ their land, labour, or stock, in bringing any commodity to market, that the quantity never should exceed the effectual demand; and it is the interest of all other people that it never should fall short of that demand.
If at any time it exceeds the effectual demand, some of the component parts of its price must be paid below their natural rate. If it is rent, the interest of the landlords will immediately prompt them to withdraw a part of their land; and if it is wages or profit, the interest of the labourers in the one case, and of their employers in the other, will prompt them to withdraw a part of their labour or stock, from this employment. The quantity brought to market will soon be no more than sufficient to supply the effectual demand. All the different parts of its price will rise to their natural rate, and the whole price to its natural price.
If, on the contrary, the quantity brought to market should at any time fall short of the effectual demand, some of the component parts of its price must rise above their natural rate. If it is rent, the interest of all other landlords will naturally prompt them to prepare more land for the raising of this commodity; if it is wages or profit, the interest of all other labourers and dealers will soon prompt them to employ more labour and stock in preparing and bringing it to market. The quantity brought thither will soon be sufficient to supply the effectual demand. All the different parts of its price will soon sink to their natural rate, and the whole price to its natural price.
The natural price, therefore, is, as it were, the central price, to which the prices of all commodities are continually gravitating. Different accidents may sometimes keep them suspended a good deal above it, and sometimes force them down even somewhat below it. But whatever may be the obstacles which hinder them from settling in this centre of repose and continuance, they are constantly tending towards it.
The whole quantity of industry annually employed in order to bring any commodity to market, naturally suits itself in this manner to the effectual demand. It naturally aims at bringing always that precise quantity thither which may be sufficient to supply, and no more than supply, that demand.
But, in some employments, the same quantity of industry will, in different years, produce very different quantities of commodities; while, in others, it will produce always the same, or very nearly the same. The same number of labourers in husbandry will, in different years, produce very different quantities of corn, wine, oil, hops, etc. But the same number of spinners or weavers will every year produce the same, or very nearly the same, quantity of linen and woollen cloth. It is only the average produce of the one species of industry which can be suited, in any respect, to the effectual demand; and as its actual produce is frequently much greater, and frequently much less, than its average produce, the quantity of the commodities brought to market will sometimes exceed a good deal, and sometimes fall short a good deal, of the effectual demand. Even though that demand, therefore, should continue always the same, their market price will be liable to great fluctuations, will sometimes fall a good deal below, and sometimes rise a good deal above, their natural price. In the other species of industry, the produce of equal quantities of labour being always the same, or very nearly the same, it can be more exactly suited to the effectual demand. While that demand continues the same, therefore, the market price of the commodities is likely to do so too, and to be either altogether, or as nearly as can be judged of, the same with the natural price. That the price of linen and woollen cloth is liable neither to such frequent, nor to such great variations, as the price of corn, every man’s experience will inform him. The price of the one species of commodities varies only with the variations in the demand; that of the other varies not only with the variations in the demand, but with the much greater, and more frequent, variations in the quantity of what is brought to market, in order to supply that demand.
The occasional and temporary fluctuations in the market price of any commodity fall chiefly upon those parts of its price which resolve themselves into wages and profit. That part which resolves itself into rent is less affected by them. A rent certain in money is not in the least affected by them, either in its rate or in its value. A rent which consists either in a certain proportion, or in a certain quantity, of the rude produce, is no doubt affected in its yearly value by all the occasional and temporary fluctuations in the market price of that rude produce; but it is seldom affected by them in its yearly rate. In settling the terms of the lease, the landlord and farmer endeavour, according to their best judgment, to adjust that rate, not to the temporary and occasional, but to the average and ordinary price of the produce.
Such fluctuations affect both the value and the rate, either of wages or of profit, according as the market happens to be either overstocked or understocked with commodities or with labour, with work done, or with work to be done. A public mourning raises the price of black cloth ( with which the market is almost always understocked upon such occasions), and augments the profits of the merchants who possess any considerable quantity of it. It has no effect upon the wages of the weavers. The market is understocked with commodities, not with labour, with work done, not with work to be done. It raises the wages of journeymen tailors. The market is here understocked with labour. There is an effectual demand for more labour, for more work to be done, than can be had. It sinks the price of coloured silks and cloths, and thereby reduces the profits of the merchants who have any considerable quantity of them upon hand. It sinks, too, the wages of the workmen employed in preparing such commodities, for which all demand is stopped for six months, perhaps for a twelvemonth. The market is here overstocked both with commodities and with labour.
But though the market price of every particular commodity is in this manner continually gravitating, if one may say so, towards the natural price; yet sometimes particular accidents, sometimes natural causes, and sometimes particular regulations of policy, may, in many commodities, keep up the market price, for a long time together, a good deal above the natural price.
When, by an increase in the effectual demand, the market price of some particular commodity happens to rise a good deal above the natural price, those who employ their stocks in supplying that market, are generally careful to conceal this change. If it was commonly known, their great profit would tempt so many new rivals to employ their stocks in the same way, that, the effectual demand being fully supplied, the market price would soon be reduced to the natural price, and, perhaps, for some time even below it. If the market is at a great distance from the residence of those who supply it, they may sometimes be able to keep the secret for several years together, and may so long enjoy their extraordinary profits without any new rivals. Secrets of this kind, however, it must be acknowledged, can seldom be long kept; and the extraordinary profit can last very little longer than they are kept.
Secrets in manufactures are capable of being longer kept than secrets in trade. A dyer who has found the means of producing a particular colour with materials which cost only half the price of those commonly made use of, may, with good management, enjoy the advantage of his discovery as long as he lives, and even leave it as a legacy to his posterity. His extraordinary gains arise from the high price which is paid for his private labour. They properly consist in the high wages of that labour. But as they are repeated upon every part of his stock, and as their whole amount bears, upon that account, a regular proportion to it, they are commonly considered as extraordinary profits of stock.
Such enhancements of the market price are evidently the effects of particular accidents, of which, however, the operation may sometimes last for many years together.
Some natural productions require such a singularity of soil and situation, that all the land in a great country, which is fit for producing them, may not be sufficient to supply the effectual demand. The whole quantity brought to market, therefore, may be disposed of to those who are willing to give more than what is sufficient to pay the rent of the land which produced them, together with the wages of the labour and the profits of the stock which were employed in preparing and bringing them to market, according to their natural rates. Such commodities may continue for whole centuries together to be sold at this high price; and that part of it which resolves itself into the rent of land, is in this case the part which is generally paid above its natural rate. The rent of the land which affords such singular and esteemed productions, like the rent of some vineyards in France of a peculiarly happy soil and situation, bears no regular proportion to the rent of other equally fertile and equally well cultivated land in its neighbourhood. The wages of the labour, and the profits of the stock employed in bringing such commodities to market, on the contrary, are seldom out of their natural proportion to those of the other employments of labour and stock in their neighbourhood.