The Term "Rent" as Historically Used.—The word rent has a striking history. The science of political economy first took shape in a country in which direct employers of labor were not, as a rule, the owners of much land. Farmers, merchants, and many manufacturers hired land and furnished only the auxiliary capital which was necessary in order to utilize it. In a practical way the earnings of land were thus separated from those of capital in other forms, since they went to a different class of persons; and in the thought of the people the charges made for the use of mere ground came to constitute a unique kind of income. If, during the last century, the land in England had been a highly mercantile commodity, and if it had been the common practice of entrepreneurs not to hire it but to buy and own it, as they bought and owned all other industrial instruments, there is little probability that land would have been considered, either in practical thought or in science, as a thing to be as broadly distinguished as it has been from all other capital goods. A business man would have measured his permanent fund of capital in pounds sterling and would have included in the amount whatever he had invested in land. As in America any representation of the capital of a corporation includes the sums invested in every productive way, and this includes the value of all land that the company holds, so in England, under a similar system of conducting business, any statement of the amount of a particular business capital would have included the whole of the productive wealth embarked in the enterprise; and in any statement of the forms of it there would have appeared, besides a list of all tools, buildings, unfinished goods, and the like, a schedule of the prices of land that the company owned and used. In "putting capital into his business" a man might buy land, in "withdrawing his capital" he might sell it; and the land in the interim would be the obvious embodiment of this part of his fund. The fact, then, that land was owned by one class of persons and let to another for hire, and that the lessees were the entrepreneurs or users of it, caused practical thought and speech to put land in a class by itself.
The Origin of the Theory of Rent.—Scientific thought powerfully strengthened this tendency. At a very early date a formula was attained for measuring the rent of land, while no satisfactory formula was, then or for a long time afterward, discovered for measuring the amount of interest. Men contented themselves with saying that the rate of interest depends on demand and supply. In the case of the rent of land the same thing might have been said, but here such a statement was not mentally satisfying, and investigators tried to ascertain why demand and supply so act as to fix the income that land yields at a certain definable amount.
The Traditional Formula for Rent.—The formula which has long been accepted as measuring the rent of a piece of land, though it bears the name of Ricardo, grew into shape under the hands of several earlier writers. In its best form of statement this principle asserts that "the rent of a piece of land is the product that can be realized by applying labor and capital to it, minus the product that can be realized by applying the same amount of labor and capital to land of the poorest grade that is in cultivation at all." The quantity of the poorest land must be left indefinite, and all that the given amount of labor and capital can economically utilize must be left at their disposal. It would not do to say that the rent of an acre of good land equals its product less that of an acre of the poorest land in cultivation tilled with the same expenditure of labor and capital. If we should select a bit of wheat land in England tilled at a large outlay in the way of work, fertilizers, drains, etc., and try the experiment of putting the same amount of labor and capital on a piece of equal size in the remotest part of Canada, we should find that, so far from securing wheat enough to pay the bills that we should incur in the way of wages and interest, we should not have enough to help us greatly in the defraying of these costs, and the cultivation of this piece of land would be a losing venture. Instead of being no-rent land, yielding merely wages and interest for the labor and capital used in connection with it, it would be minus-rent land, deducting something from the earnings which the agents combined with it might elsewhere secure. In order to utilize such land at all, one must till it in what is termed an extensive rather than an intensive way, putting a small amount rather than a large amount of work and expenditure on it. By tilling ten acres of a remote and sterile farm with as much labor and other outlay as a very good acre of land in England receives, one can perhaps get enough to pay the required wages and interest. In general no-rent land is commonly utilized in an extensive way and very good land in an intensive way; and in stating the old formula for rent we need to be careful to make it mean that the rent of the good piece is its total product less the product that can be had by taking from the good piece the labor and capital it now absorbs and setting them at work on a piece of the poorest land which is enough larger than the good one to enable us to secure a crop which will be worth just the amount of wages and interest we must pay. The larger size of the poor piece of land is an essential condition.
Real Significance of Rent Formula.—It will be seen that this formula amounts to saying that the rent of land is what the land itself adds to the marginal product of labor and capital. Put a certain amount of labor and capital on a piece of land of good quality, and you get a certain amount of product. Withdraw the land from the combination, and you force the labor and capital to become marginal increments of these agents. They must go elsewhere and get what they can. One alternative that is open to them is that of seeking out land of a grade so poor that it has not been previously utilized and doing what they can to get a product out of it. Whatever they can make such land yield is, in an economic sense, wholly their own product. There is an indefinite quantity of this kind of land to be had, and wherever labor and capital utilize any part of it, they can have all that they produce. Now if we subtract what they there create from what was created when they were working on the good land, we have the rent of that land.
Rent as a Product Imputable to Land.—The difference between what the labor and capital produce at the margin of cultivation of land and what they can produce on good land, or land that lies within the margin, is clearly attributable to the qualities of the land itself. Given X units of labor and Y units of capital, combine with them no land except such as is too poor to have been previously utilized, and you get a certain product. It is the product of the labor and capital using something which is free to any one. Now put a piece of good land into the combination; to the X units of labor and Y units of capital add a piece of productive land and see what you can create. We do this by taking these units of labor and capital away from the worthless marginal land and setting them to tilling that which is of the better quality. The product is of course larger than they got before, and the difference measures what the land itself adds to the output of the other agents in the combination. The true conception of rent is that of the specific addition which land makes to the product of other agents used in connection with it. There are various ways of measuring this addition, but the method just used will at least show that the presence of the good land is the cause of the excess of product which given amounts of labor and capital secure over what they could create on land of the poorest quality.
Rent as a Differential Product.—In the early statements of the rent law it was not said that the rent of a piece of land is the product specifically attributable to it. If it had been, the chances are large that a much broader and more scientific use of the rent formula would have resulted. The law of rent, as it was actually stated, made it consist of a differential amount. It was what a given amount of labor and capital would produce under one set of conditions minus what they would produce under another. Since it is the presence or the absence of the productive land which makes the only difference between the two conditions, rent, even as it is thus defined, is really the amount of product specifically attributable to the land. It is what is created when the land is used in excess of what would be created if it were not used and if the coÖperating agents did the best they could without it. We may use, as the most general formula for the rent of land, the contribution which land itself makes to the product of social industry.
If we use the same method in measuring the rent of land which we used in measuring the wages of labor and the returns of capital, we shall represent the rent of a given piece of land as the sum of a series of differential amounts. In the accompanying figure the vertical belts bounded by lines rising from the letters A, B, C, etc., represent the products realized by applying successive increments of labor and capital to a given piece of land; and the horizontal lines running toward the left from A´, B´, C´, etc., separate the wages and interest from the amounts that are successively added to rent. When one composite unit of labor and capital is working, its product and its pay is measured by the belt between the line AA´ and the line NN´. A second composite unit produces the amount represented by the area between AA´ and BB´, and that is the amount which each unit separately considered will produce and get as its pay. This leaves the area between the horizontal line running from B´ and the section of the descending curve as the rent of the land. A third unit of labor and capital produces what is represented by the area between BB´ and CC´, and this becomes the standard of pay for all units, leaving the enlarged area above the horizontal line at C´ as rent. In the end there are ten units of labor and capital. Their total earnings are expressed by the area of the rectangle below the horizontal line running from J´, and the sum of all the areas above that line is rent.
The Intensive Margin of Cultivation.—The extensive margin of cultivation is the land that is adjacent to an imaginary boundary line separating the grades of land that are good enough to be used from those that are too poor to be used. There is, however, what may be called the intensive margin of cultivation. A given bit of land is said to be cultivated more and more intensively when more and more labor and capital are used on it. Land is subject to what is called the law of diminishing returns.
Law of Diminishing Returns.—The more labor and capital you employ on a given piece of land, the less you will get as a product for each unit of these agents. What the last unit of labor adds to the antecedent output is less than was added by any of the other units, and the same is true of the last unit of capital. As we continue the process of enlarging the working force and adding to the working appliances, we reach a point at which it is better to cease putting new men with their equipment at work on this piece of land and to set them working on a bit of land so poor that it was not formerly utilized at all. We may assume here that what a man needs, in the way of auxiliary capital, goes with him, whether he joins a force that is working on good land or migrates to a less productive region. He will go if it will pay him to do it. In this way we make a sort of dual unit of labor and capital and apply a series of such units to land.
Ground Capital and Auxiliary Capital Distinguished.—Land itself is a component part of the permanent fund of productive wealth to which we have given the generic name capital. It differs from other capital goods in that it does not wear out and require renewing. Working appliances, however, as they wear out and are replaced, constitute a permanent fund of auxiliary capital, and we shall apply this term to the abiding stock of such instruments except in connections in which the adjective is not needed, because it is clear that the land, or ground capital, cannot be referred to. In dynamic studies the distinction between land and auxiliary capital becomes very important.
How the Intensive Margin locates the Extensive One.—The labor and the auxiliary capital that betake themselves to new land of the inferior quality represent an overflow from the better land. As long as men can do as well by staying where they are as they can by migrating to new regions, where inferior lands are to be had, they will stay; but when they incur a loss by staying, they move. What a laborer can create by securing the use of an equipment and adding himself to the force that is at work on some good farm, can be approximately estimated; and if there is somewhere a piece of land not thus far used to which he can remove, and if, by going to work upon it, he can create any more than he created while working on the older farm and taking his products as his pay, he will till that poor piece. But neither he nor any one else will till a piece that is still less productive. If any one were to set himself working on land of still poorer quality, he would lose and not gain by the change, since there he would produce even less than he can when he is the last man set working on the good piece.
To what Extent the Movement of Labor and that of Capital are Interdependent.—The early statements of the law of rent did not usually define the intensive margin of cultivation in connection with labor and capital separately, but spoke of these two agents as employed together upon land in quantities increasing up to a limit beyond which both labor and capital would best be employed elsewhere. The supposition that labor and capital go thus together from one grade of land to another is only approximately accurate. If we consider one man and five hundred dollars' worth of productive wealth as a dual unit of labor and capital, and add such units, one after another, to the forces at work on a tract of good land, we shall reach a point at which it will not be profitable to increase the amount of one of the agents, while it will still be profitable to increase the amount of the other. It will perhaps not pay to use any more capital, but it may still pay to add to the number of workers. On land that is tilled more and more intensively, labor and capital are not tied together in fixed proportions in such a way that, when there is more of one of them used, there is proportionately more of the other. Moreover, when a unit of one of them abandons a piece of land and goes elsewhere, there is no probability that exactly one unit of the other will do the same. There is, indeed, no such thing as a dual unit of labor and capital that can be thought of as moving to and fro among different employments till it finds the point at which, as a dual unit, it can create its largest product. These two agents so locate themselves that a final unit of each one, separately considered, produces as much where it is as it can produce anywhere else.
It is, however, to be noted that the amount of labor that can profitably be employed on a piece of land grows larger the more capital there is employed in connection with it. An acre of land and a thousand dollars' worth of auxiliary funds can enable more men to get good returns than can an acre combined with a fund of five hundred dollars. Conversely, the more men there are working on the area, the more auxiliary capital it pays to use there. If there are five men working on a small field it may be that a thousand dollars may be well invested in aiding them, while with only one man it would not pay to use so large an amount. The capital and the labor, as it were, attract each other. Additional capital attracts further labor, and vice versa, till a condition is reached in which neither of them can so well be used on that particular piece of land as it can elsewhere. Each one has then been used on this area up to its own intensive-marginal limit. So also when one of these agents betakes itself to marginal land, it attracts the other agent thither. When there are ten men on the poorest piece of land in a locality, it is possible to make a considerable amount of capital at that point pay the return generally prevailing, whereas only a small amount would pay it if there were only five men working. With a thousand dollars invested on that land more laborers will be lured thither by the prospect of fair returns than would be lured thither if there were only half as much capital. The general apportionment of both agents tends to be such that a unit of either is as well off on one piece of land as on another, and each is as well off at the extensive margin of cultivation of land as it is on the intensive margin.
Labor and Capital combined in Varying Amounts.—The amount of capital that is combined with a unit of labor is not often the same on good land as it is on poor. The proportions in which labor and capital will be combined on the marginal field will be almost certain to vary from those in which they were combined in the better field from which they came. It may be that they leave industries in which an average man uses an equipment worth a thousand dollars. When they reach the margin of cultivation, capital may be so scarce that the thousand dollars will not stay in the hands of the one man but will divide itself among several.
The General Law of the Extension of the Margin of Cultivation.—Sometimes, when labor moves to new land that is now at the margin, it takes its new equipment with it; but such land is not always tilled by independent settlers. Employing farmers may set men working on it and pay them all that they produce; and the farmers may furnish the men with capital of their own or borrow capital for them to use. In either case a static condition requires the equalizing of the productivity of labor at the intensive margin with that of labor at the extensive margin; and it requires a similar leveling of the productivity of capital at the two margins. When this leveling has taken place in both cases, the all-around marginal product of labor fixes the rate of wages, and that of capital fixes the rate of interest. What a man creates on the good land and with the adequate capital, or on poor land with proportionate capital,—in any occupation on land of either grade,—determines the pay that he and other men can get. It constitutes in itself the wages of labor. In so far as the overflow of labor and capital into any one limited region of marginal land is concerned, the full statement is this: that the margin of utilization of land will be extended to the point at which a unit of labor, using as much of the marginal land as it is economical to use, and such amount of auxiliary capital as is economical to combine with this unit of labor and the land it occupies, will create a product equal to the wages of the unit of labor as they are determined by the product it created when it was employed on the good land and in connection with the full equipment of auxiliary capital.
The Rent of a Fund of Capital.—We saw that one unit of labor employed in connection with a given amount of capital produces more than does a second; that the second produces more than the third; and that, if we continue to supply units one at a time, the last unit in the series produces the least of all. Wages are fixed by the amount that one unit of labor produces when the working force is complete, and that is what is contributed to the general product by the unit of labor which comes last in the imaginary series by which the force is built up. Owing to the more favorable conditions under which, in their time, the earlier units worked, they were able to produce surpluses above the amount produced by the last one. When they entered the field they were supplied with excessive amounts of capital. The first one had the whole fund coÖperating with it, till it had to share it with the second; and after that each had a half of it till they had to share evenly with a third, etc. We have seen that all the surpluses appearing in connection with the earlier units are attributable in reality to capital. The area BCD (page 139) represents the amount by which the presence of an excess of capital increases the products attributable to the earlier units of labor. It represents the sum of all the differences between the products of the earlier units and the product of that final one which in the end sets the standard of productivity of labor. It might be called the rent of the fund of capital. It is composed of a sum of differences exactly like those which constitute the rent of a piece of land.
The Rent of a Permanent Force of Labor.—In the figure on page 148, the working force was supposed to be fixed in amount, the capital increasing by increments, or as some earlier economists would have said, by "doses" along the line A´E´. The last unit of capital produces the amount D´E´, and all the capital produces A´B´D´E´, while products of the earlier units of capital, as they come successively into the field and are used by an excessively large labor force, are represented by the area B´C´D´. Here this area represents what may be called the rent of the force of labor, since it is a sum of surpluses that, again, are entirely akin to those that constitute the rent of a piece of land.
A Question of Nomenclature.—It may be an open question, as a matter of mere nomenclature, whether these surpluses which are thus traceable to a permanent fund of capital, on the one hand, and to a permanent force of labor, on the other, can with advantage be called rents. In this treatise we do not think it best to employ that nomenclature. What is not uncertain is that these gains are measurable by the same formula that measures the rent of a piece of land. If the essential thing about rent were that it is a material product and consists of a sum of differential quantities, these incomes certainly would be rents. Popular thought, however, attaches another meaning to this term, and we therefore limit ourselves to saying that these differential incomes or surpluses may be determined in amount by the principle of rent. They can be described and measured exactly as the Ricardians described the income of landlords.[1]
[1] The term rent has even been applied to surpluses of a psychological kind. Certain gains that men get consist purely in pleasures or in reduced pains or sacrifices, and a few writers have applied to such subjective gains the term rent. If a man buys a barrel of flour for five dollars and gets out of it a service that is a hundred times as great as he could get from some other article which he buys for the same amount, this surplus of pleasure may be called, by a figure of speech, "consumers' rent"; and if the essence of rent were the fact that it can be made to take the form of a surplus or difference, the name would be well chosen, though there is danger that by this use of the term science may divorce itself from practical thought and life. If we take all the barrels of flour that a man uses in ten years, there is one which is marginal, because it is worth to the man only enough to offset the sacrifice he incurs in getting it. All the others are worth more. We can arrange them in a scale in the order of their importance, the most necessary one coming first and the least important one last; and we can compare the service which each one renders with that rendered by the last, and measure the surplus of good which each one does to the user. There is here in operation a law of diminishing subjective returns. Early units consumed afford more pleasure than do later ones. There results a series of surplus gains, and the sum of all these surpluses makes a total of net benefit,—is a gain that is not offset by a compensatory sacrifice. The last barrel of flour on the list is worth just what it costs, and all the others are worth more. They give the consumer a surplus of satisfaction for which he pays nothing. The sum of the excesses of service rendered by all the earlier barrels constitutes what has been called the consumers' rent, realized in this case from the entire supply of flour used by the man. In the manner in which it is conceived and measured this gain has a kinship to genuine rent.
This surplus is an effect on a man himself. It is not anything outward or tangible. It exists only in the man's sensations, and is as far as possible from being a concrete income in material form traceable to some particular agent. It can be measured and described in ways that are quite akin to the manner in which the product of land is measured and described. Each consists of the sum of a series of surpluses or differential amounts, and each, moreover, represents a gain which is not offset by any corresponding subjective cost. The rent of land must be paid by an entrepreneur and is a cost in the same sense in which wages and interest are so; but the owner of the land did not create it by personal effort or sacrifice.
Analogies between the product of land, or rent, and the special gains of consumers from the more important parts of their consumption do exist, but they are overbalanced by essential differences; and it is better to use the term rent only in describing the specific contribution to the material product of industry which a concrete and material agent makes.
