For a general understanding of the law of rent the following table will show how, under constant increase of population (represented by four different advances of population, in the [pg 240] first column), first the best and then the poorer lands are brought into cultivation. We will suppose (1) that the most fertile land, A, at first pays no rent; then (2), when more food is wanted than land A can supply, it will be profitable to till land B, but which, as yet, pays no rent. But if eighteen bushels are a sufficient return to a given amount of labor and capital, then when an equal amount of labor and capital engaged on A returns twenty-four bushels, six of that are beyond the ordinary profit, and form the rent on land A, and so on; C will next be the line of comparison, and then D; as the poorer soils are cultivated, the rent of A increases:
| Population Increase. | A | B | C | D | ||||
| 24 bushels | 18 bushels | 12 bushels | 6 bushels | |||||
| Total product | Rent in Bushels | Total product | Rent in Bushels | Total product | Rent in Bushels | Total product | Rent in Bushels | |
| I. | 24 | 0 | .. | .. | .. | .. | .. | .. |
| II. | 24 | 6 | 18 | 0 | .. | .. | .. | .. |
| III. | 24 | 12 | 18 | 6 | 12 | 0 | .. | .. |
| IV. | 24 | 18 | 18 | 12 | 12 | 6 | 6 | 0 |
§ 5. Opposing Views of the Law of Rent.
Under the name of rent, many payments are commonly included, which are not a remuneration for the original powers of the land itself, but for capital expended on it. The buildings are as distinct a thing from the farm as the stock or the timber on it; and what is paid for them can no more be called rent of land than a payment for cattle would be, if it were the custom that the landlord should stock the farm for the tenant. The buildings, like the cattle, are not land, but capital, regularly consumed and reproduced; and all payments made in consideration for them are properly interest.
But with regard to capital actually sunk in improvements, and not requiring periodical renewal, but spent once for all in giving the land a permanent increase of productiveness, it appears to me that the return made to such capital loses altogether the character of profits, and is governed by the principles of rent. It is true that a landlord will not expend capital in improving his estate unless he expects from the improvement an increase of income surpassing the interest [pg 241] of his outlay. Prospectively, this increase of income may be regarded as profit; but, when the expense has been incurred and the improvement made, the rent of the improved land is governed by the same rules as that of the unimproved.
Mr. Carey (as well as Bastiat) has declared that there is a law of increasing returns from land. He points out that everything now existing could be reproduced to-day at a less cost than that involved in its original production, owing to our advance in skill, knowledge, and all the arts of production; that, for example, it costs less to make an axe now than it did five hundred years ago; so also with a farm, since a farm of a given amount of productiveness can be brought into cultivation at less cost to-day than that originally spent upon it. The gain of society has, we all admit, been such that we produce almost everything at a less cost now than long ago; but to class a farm and an axe together overlooks, in the most remarkable way, the fact that land can not be created by labor and capital, while axes can, and that too indefinitely. Nor can the produce from the land be increased indefinitely at a diminishing cost. This is sometimes denied by the appeal to facts: “It can be abundantly proved that, if we take any two periods sufficiently distant to afford a fair test, whether fifty or one hundred or five hundred years, the production of the land relatively to the labor employed upon it has progressively become greater and greater.”[182] But this does not prove that an existing tendency to diminishing returns has not been more than offset by the progress of the arts and improvements. “The advance of a ship against wind and tide is [no] proof that there is no wind and tide.”
In a work entitled “The Past, the Present, and the Future,” Mr. Carey takes [a] ground of objection to the Ricardo theory of rent, namely, that in point of historical fact the lands first brought under cultivation are not the most fertile, but the barren lands. “We find the settler invariably occupying the high and thin lands requiring little clearing and no drainage. With the growth of population and wealth, other soils yielding a larger return to labor are always brought into activity, with a constantly increasing return to the labor expended upon them.”
In whatever order the lands come into cultivation, those [pg 242] which when cultivated yield the least return, in proportion to the labor required for their culture, will always regulate the price of agricultural produce; and all other lands will pay a rent simply equivalent to the excess of their produce over this minimum. Whatever unguarded expressions may have been occasionally used in describing the law of rent, these two propositions are all that was ever intended by it. If, indeed, Mr. Carey could show that the return to labor from the land, agricultural skill and science being supposed the same, is not a diminishing return, he would overthrow a principle much more fundamental than any law of rent. But in this he has wholly failed.
Another objection taken against the law of diminishing returns, and so against the law of rent, is that the potential increase of food, e.g., of a grain of wheat, is far greater than that of man.[183] No one disputes the fact that one grain of wheat can reproduce itself more times than man, and that too in a geometric increase; but not without land. A grain of wheat needs land in which it can multiply itself, and this necessary element of its increase is limited; and it is the very thing which limits the multiplication of the grains of wheat. On the same piece of land, one can not get more than what comes from one act of reproduction in the grain. If one grain produces 100 of its kind, doubling the capital will not repeatedly cause a geometric increase in the ratio of reproduction of each grain on this same land, so that one grain, by one process, produces of its kind 200, 400, 800, or 1,600, because you can not multiply the land in any such ratio as would accompany this potential reduplication of the grain. This objection would not seem worth answering, were it not that it furnishes some difficulty to really honest inquirers.