the ordinary rate of profit.
As, however, differences of fertility slide into one another by insensible gradations; and differences of accessibility, that is, of distance from markets do the same; and since there is land so barren that it could not pay for its cultivation at any price; it is evident that, whatever the [pg 235] price may be, there must in any extensive region be some land which at that price will just pay the wages of the cultivators, and yield to the capital employed the ordinary profit, and no more. Until, therefore, the price rises higher, or until some improvement raises that particular land to a higher place in the scale of fertility, it can not pay any rent. It is evident, however, that the community needs the produce of this quality of land; since, if the lands more fertile or better situated than it could have sufficed to supply the wants of society, the price would not have risen so high as to render its cultivation profitable. This land, therefore, will be cultivated; and we may lay it down as a principle that, so long as any of the land of a country which is fit for cultivation, and not withheld from it by legal or other factitious obstacles, is not cultivated, the worst land in actual cultivation (in point of fertility and situation together) pays no rent.
§ 3. The Rent of Land is the Excess of its Return above the Return to the worst Land in Cultivation.
If, then, of the land in cultivation, the part which yields least return to the labor and capital employed on it gives only the ordinary profit of capital, without leaving anything for rent, a standard [i.e., the “margin of cultivation”] is afforded for estimating the amount of rent which will be yielded by all other land. Any land yields just as much more than the ordinary profits of stock as it yields more than what is returned by the worst land in cultivation. The surplus is what the farmer can afford to pay as rent