Page:The wealth of nations, volume 1.djvu/161

 most proper machinery for executing the work of each, and it is, therefore, more likely to be invented. There are many commodities, therefore, which, in consequence of these improvements, come to be produced by so much less labor than before, that the increase of its price is more than compensated by the diminution of its quantity.

HE rise and fall in the profits of stock depend upon the same causes with the rise and fall in the wages of labor, the increasing or declining state of the wealth of the society; but those causes affect the one and the other very differently.

The increase of stock, which raises wages, tends to lower profit. When the stocks of many rich merchants are turned into the same trade, their mutual competition naturally tends to lower its profit; and when there is a like increase of stock in all the different trades carried on in the same society, the same competition must produce the same effect in them all.

It is not easy, it has already been observed, to ascertain what are the average wages of labor, even in a particular place, and at a particular time. We can, even in this case, seldom determine more than what are the most usual wages. But even this can seldom be done with regard to the profits of stock. Profit is so very fluctuating that the person who carries on a particular trade cannot always tell you himself what is the average of his annual profit. It is affected, not only by every variation of price in the commodities which