There is in every society or neighbourhood an ordinary or average rate, both of wages and profit, in every different employment of labour and stock. This rate is naturally regulated, as I shall shew hereafter, partly by the general circumstances of the society, their riches or poverty, their advancing, stationary, or declining condition, and partly by the particular nature of each employment. There is likewise in every society or neighbourhood an ordinary or average rate of rent, which is regulated, too, as I shall shew hereafter, partly by the general circumstances of the society or neighbourhood in which the land is situated, and partly by the natural or improved fertility of the land. These ordinary or average rates may be called the natural rates of wages, profit and rent, at the time and place in which they commonly prevail. When the price of any commodity is neither more nor less than what is sufficient to pay the rent of the land, the wages of the labour, and the profits of the stock employed in raising, preparing, and bringing it to market, according to their natural rates, the commodity is then sold for what may be called its natural price. The commodity is then sold precisely for what it is worth, or for what it really costs the person who brings it to market; for though, in common language, what is called the prime cost of any commodity does not comprehend the profit of the person who is to sell it again, yet, if he sells it at a price which does not allow him the ordinary rate of profit in his neighbourhood, he is evidently a loser by the trade; since, by employing his stock in some other way, he might have made that profit. His profit, besides, is his revenue, the proper fund of his subsistence. As, while he is preparing and bringing the goods to market, he advances to his workmen their wages, or their subsistence; so he advances to himself, in the same manner, his own subsistence, which is generally suitable to the profit which he may reasonably expect from the sale of his goods. Unless they yield him this profit, therefore, they do not repay him what they may very properly be said to have really cost him. Though the price, therefore, which leaves him this profit, is not always the lowest at which a dealer may sometimes sell his goods, it is the lowest at which he is likely to sell them for any considerable time; at least where there is perfect liberty, or where he may change his trade as often as he pleases. The actual price at which any commodity is commonly sold, is called its market price. It may either be above, or below, or exactly the same with its natural price.