# Principles of Political Economy (J.S. Mill, 1871), vol. 1/Book III, Chapter V

CHAPTER V.
OF RENT,IN ITS RELATION TO VALUE.
§ 1. We have investigated the laws which determine the value of two classes of commodities: the small class which, being limited to a definite quantity, have their value entirely determined by demand and supply, save that their cost of production (if they have any) constitutes a minimum below which they cannot permanently fall; and the large class, which can be multiplied ad libitum by labour and capital, and of which the cost of production fixes the maximum as well as the minimum at which they can permanently exchange. But there is still a third kind of commodities to be considered: those which have, not one, but several costs of production: which can always be increased in quantity by labour and capital, but not by the same amount of labour and capital; of which so much may be produced at a given cost, but a further quantity not without a greater cost. These commodities form an intermediate class, partaking of the character of both the others. The principal of them is agricultural produce. We have already made abundant reference to the fundamental truth, that in agriculture, the state of the art being given, doubling the labour does not double the produce; that if an increased quantity of produce is required, the additional supply is obtained at a greater cost than the first. Where a hundred quarters of corn are all that is at present required from the lands of a given village, if the growth of population made it necessary to raise a hundred more, either by breaking up worse land now uncultivated, or by a more elaborate cultivation of the land already under the plough, the additional hundred, or some part of them at least, ​might cost double or treble as much per quarter as the former supply.
If the first hundred quarters were all raised at the same expense (only the best land being cultivated); and if that expense would be remunerated with the ordinary profit by a price of 20s. the quarter; the natural price of wheat, so long as no more than that quantity was required, would be 20s.; and it could only rise above, or fall below that price, from vicissitudes of seasons, or other casual variations in supply. But if the population of the district advanced, a time would arrive when more than a hundred quarters would be necessary to feed it. We must suppose that there is no access to any foreign supply. By the hypothesis, no more than a hundred quarters can be produced in the district, unless by either bringing worse land into cultivation, or altering the system of culture to a more expensive one. Neither of these things will be done without a rise in price. This rise of price will gradually be brought about by the increasing demand. So long as the price has risen, but not risen enough to repay with the ordinary profit the cost of producing an additional quantity, the increased value of the limited supply partakes of the nature of a scarcity value. Suppose that it will not answer to cultivate the second best land, or land of the second degree of remoteness, for a less return than 25s. the quarter; and that this price is also necessary to remunerate the expensive operations by which an increased produce might be raised from land of the first quality. If so, the price will rise, through the increased demand, until it reaches 25s. That will now be the natural price; being the price without which the quantity, for which society has a demand at that price, will not be produced. At that price, however, society can go on for some time longer; could go on perhaps for ever, if population did not increase. The price, having attained that point, will not again permanently recede (though it may fall temporarily from accidental abundance); nor will it advance further so long as society can obtain the ​supply it requires without a second increase of the cost of production.
I have made use of Price in this reasoning, as a convenient symbol of Value, from the greater familiarity of the idea; and I shall continue to do so as far as may appear to be necessary.
In the case supposed, different portions of the supply of corn have different costs of production. Though the 20, or 50, or 150 quarters additional have been produced at a cost proportional to 25s., the original hundred quarters per annum are still produced at a cost only proportional to 20s. This is self-evident, if the original and the additional supply are produced on different qualities of land. It is equally true if they are produced on the same land. Suppose that land of the best quality, which produced 100 quarters at 20s., has been made to produce 150 by an expensive process, which it would not answer to undertake without a price of 25s. The cost which requires 25s. is incurred for the sake of 50 quarters alone: the first hundred might have continued for ever to be produced at the original cost, and with the benefit, on that quantity, of the whole rise of price caused by the increased demand: no one, therefore, will incur the additional expense for the sake of the additional fifty, unless they alone will pay for the whole of it. The fifty, therefore, will be produced at their natural price, proportioned to the cost of their production; while the other hundred will now bring in 5s. a quarter more than their natural price—than the price corresponding to, and sufficing to remunerate, their lower cost of production.
If the production of any, even the smallest, portion of the supply, requires as a necessary condition a certain price, that price will be obtained for all the rest. We are not able to buy one loaf cheaper than another because the corn from which it was made, being grown on a richer soil, has cost less to the grower. The value, therefore, of an article (meaning its natural, which is the same with its average value) is ​mined by the cost of that portion of the supply which is produced and brought to market at the greatest expense. This is the Law of Value of the third of the three classes into which all commodities are divided.
§ 2. If the portion of produce raised in the most unfavourable circumstances, obtains a value proportioned to its cost of production; all the portions raised in more favourable circumstances, selling as they must do at the same value, obtain a value more than proportioned to their cost of production. Their value is not, correctly speaking, a scarcity value, for it is determined by the circumstances of the production of the commodity, and not by the degree of dearness necessary for keeping down the demand to the level of a limited supply. The owners, however, of those portions of the produce enjoy a privilege; they obtain a value which yields them more than the ordinary profit. If this advantage depends upon any special exemption, such as being free from a tax, or upon any personal advantages, physical or mental, or any peculiar process only known to themselves, or upon the possession of a greater capital than other people, or upon various other things which might be enumerated, they retain it to themselves as an extra gain, over and above the general profits of capital, of the nature, in some sort, of a monopoly profit. But when, as in the case which we are more particularly considering, the advantage depends on the possession of a natural agent of peculiar quality, as for instance of more fertile land than that which determines the general value of the commodity; and when this natural agent is not owned by themselves: the person who does own it, is able to exact from them, in the form of rent, the whole extra gain derived from its use. We are thus brought by another road to the Law of Rent, investigated in the concluding chapter of the Second Book. Rent, we again see, is the difference between the unequal returns to different parts of the capital employed on the soil. Whatever surplus any portion of ​agricultural capital produces, beyond what is produced by the same amount of capital on the worst soil, or under the most expensive mode of cultivation, which the existing demands of society compel a recourse to; that surplus will naturally be paid as rent from that capital, to the owner of the land on which it is employed.
It was long thought by political economists, among the rest even by Adam Smith, that the produce of land is always at a monopoly value, because (they said) in addition to the ordinary rate of profit, it always yields something further for rent. This we now see to be erroneous. A thing cannot be at a monopoly value, when its supply can be increased to an indefinite extent if we are only willing to incur the cost. If no more corn than the existing quantity is grown, it is because the value has not risen high enough to remunerate any one for growing it. Any land (not reserved for other uses, or for pleasure) which at the existing price, and by the existing processes, will yield the ordinary profit, is tolerably certain, unless some artificial hindrance intervenes, to be cultivated, although nothing may be left for rent. As long as there is any land fit for cultivation, which at the existing price cannot be profitably cultivated at all, there must be some land a little better, which will yield the ordinary profit, but allow nothing for rent: and that land, if within the boundary of a farm, will be cultivated by the farmer; if not so, probably by the proprietor, or by some other person on sufferance. Some such land at least, under cultivation, there can scarcely fail to be.
Rent, therefore, forms no part of the cost of production which determines the value of agricultural produce. Circumstances no doubt may be conceived in which it might do so, and very largely too. We can imagine a country so fully peopled, and with all its cultivable soil so completely occupied, that to produce any additional quantity would require more labour than the produce would feed: and if we suppose this to be the condition of the whole world, or of a country ​debarred from foreign supply, then, if population continued increasing, both the land and its produce would really rise to a monopoly or scarcity price. But this state of things never can have really existed anywhere, unless possibly in some small island cut off from the rest of the world; nor is there any danger whatever that it should exist. It certainly exists in no known region at present. Monopoly, we have seen, can take effect on value, only through limitation of supply. In all countries of any extent there is more cultivable land than is yet cultivated; and while there is any such surplus, it is the same thing, so far as that quality of land is concerned, as if there were an infinite quantity. What is practically limited in supply is only the better qualities; and even for those, so much rent cannot be demanded as would bring in the competition of the lands not yet in cultivation; the rent of a piece of land must be somewhat less than the whole excess of its productiveness over that of the best land which it is not yet profitable to cultivate; that is, it must be about equal to the excess above the worst land which it is profitable to cultivate. The land or the capital most unfavourably circumstanced among those actually employed, pays no rent; and that land or capital determines the cost of production which regulates the value of the whole produce. Thus rent is, as we have already seen, no cause of value, but the price of the privilege which the inequality of the returns to different portions of agricultural produce confers on all except the least favoured portions.
Rent, in short, merely equalizes the profits of different farming capitals, by enabling the landlord to appropriate all extra gains occasioned by superiority of natural advantages. If all landlords were unanimously to forego their rent, they would but transfer it to the farmers, without benefiting the consumer; for the existing price of corn would still be an indispensable condition of the production of part of the existing supply, and if a part obtained that price the whole would obtain it. Rent, therefore, unless artificially ​increased by restrictive laws, is no burthen on the consumer: it does not raise the price of corn, and is no otherwise a detriment to the public, than inasmuch as if the state had retained it, or imposed an equivalent in the shape of a land-tax, it would then have been a fund applicable to general instead of private advantage.
§ 3.Agricultural productions are not the only commodities which have several different costs of production at once, and which, in consequence of that difference, and in proportion to it, afford a rent. Mines are also an instance. Almost all kinds of raw material extracted from the interior of the earth—metal, coals, precious stones, &c., are obtained from mines differing considerably in fertility, that is, yielding very different quantities of the product to the same quantity of labour and capital. This being the case, it is an obvious question, why are not the most fertile mines so worked as to supply the whole market? No such question can arise as to land; it being self-evident, that the most fertile lands could not possibly be made to supply the whole demand of a fully-peopled country; and even of what they do yield, a part is extorted from them by a labour and outlay as great as that required to grow the same amount on worse land. But it is not so with mines; at least, not universally. There are, perhaps, cases in which it is impossible to extract from a particular vein, in a given time, more than a certain quantity of ore, because there is only a limited surface of the vein exposed, on which more than a certain number of labourers cannot be simultaneously employed. But this is not true of all mines. In collieries, for example, some other cause of limitation must be sought for. In some instances the owners limit the quantity raised, in order not too rapidly to exhaust the mine: in others there are said to be combinations of owners, to keep up a monopoly price by limiting the production. Whatever be the causes, it is a fact that mines of different degrees of richness are in operation, and ​since the value of the produce must be proportional to the cost of production at the worst mine (fertility and situation taken together), it is more than proportional to that of the best. All mines superior in produce to the worst actually worked, will yield, therefore, a rent equal to the excess. They may yield more; and the worst mine may itself yield a rent. Mines being comparatively few, their qualities do not graduate gently into one another, as the qualities of land do; and the demand may be such as to keep the value of the produce considerably above the cost of production at the worst mine now worked, without being sufficient to bring into operation a still worse. During the interval, the produce is really at a scarcity value.
Fisheries are another example. Fisheries in the open sea are not appropriated, but fisheries in lakes or rivers almost always are so, and likewise oyster-beds or other particular fishing grounds on coasts. We may take salmon fisheries as an example of the whole class. Some rivers are far more productive in salmon than others. None, however, without being exhausted, can supply more than a very limited demand. The demand of a country like England can only be supplied by taking salmon from many different rivers of unequal productiveness, and the value must be sufficient to repay the cost of obtaining the fish from the least productive of these. All others, therefore, will if appropriated afford a rent equal to the value of their superiority. Much higher than this it cannot be, if there are salmon rivers accessible which from distance or inferior productiveness have not yet contributed to supply the market. If there are not, the value, doubtless, may rise to a scarcity rate, and the worst fisheries in use may then yield a considerable rent.
Both in the case of mines and of fisheries, the natural order of events is liable to be interrupted by the opening of a new mine, or a new fishery, of superior quality to some of those already in use. The first effect of such an incident is an increase of the supply; which of course lowers the value ​to call forth an increased demand. This reduced value may be no longer sufficient to remunerate the worst of the existing mines or fisheries, and these may consequently be abandoned. If the superior mines or fisheries, with the addition of the one newly opened, produce as much of the commodity as is required at the lower value corresponding to their lower cost of production, the fall of value will be permanent, and there will be a corresponding fall in the rents of those mines or fisheries which are not abandoned. In this case, when things have permanently adjusted themselves, the result will be, that the scale of qualities which supply the market will have been cut short at the lower end, while a new insertion will have been made in the scale at some point higher up; and the worst mine or fishery in use—the one which regulates the rents of the superior qualities and the value of the commodity—will be a mine or fishery of better quality than that by which they were previously regulated.
Land is used for other purposes than agriculture, especially for residence; and when so used, yields a rent, determined by principles similar to those already laid down. The ground rent of a building, and the rent of a garden or park attached to it, will not be less than the rent which the same land would afford in agriculture: but may be greater than this to an indefinite amount; the surplus being either in consideration of beauty or of convenience, the convenience often consisting in superior facilities for pecuniary gain. Sites of remarkable beauty are generally limited in supply, and therefore, if in great demand, are at a scarcity value. Sites superior only in convenience are governed as to their value by the ordinary principles of rent. The ground rent of a house in a small village is but little higher than the rent of a similar patch of ground in the open fields: but that of a shop in Cheapside will exceed these, by the whole amount at which people estimate the superior facilities of money-making in the more crowded place. The rents of wharfage, dock and harbour room, water-power, and many other privileges, may be analysed on similar principles.
§ 4.Cases of extra profit analogous to rent, are more frequent in the transactions of industry than is sometimes supposed. Take the case, for example, of a patent, or exclusive privilege for the use of a process by which cost of production is lessened. If the value of the product continues to be regulated by what it costs to those who are obliged to persist in the old process, the patentee will make an extra profit equal to the advantage which his process possesses over theirs. This extra profit is essentially similar to rent, and sometimes even assumes the form of it; the patentee allowing to other producers the use of his privilege, in consideration of an annual payment. So long as he, and those whom he associates in the privilege, do not produce enough to supply the whole market, so long the original cost of production, being the necessary condition of producing a part, will regulate the value of the whole; and the patentee will be enabled to keep up his rent to a full equivalent for the advantage which his process gives him. In the commencement indeed he will probably forego a part of this advantage for the sake of underselling others: the increased supply which he brings forward will lower the value, and make the trade a bad one for those who do not share in the privilege; many of whom therefore will gradually retire, or restrict their operations, or enter into arrangements with the patentee: as his supply increases theirs will diminish, the value meanwhile continuing slightly depressed. But if he stops short in his operations before the market is wholly supplied by the new process, things will again adjust themselves to what was the natural value before the invention was made, and the benefit of the improvement will accrue solely to the patentee.
The extra gains which any producer or dealer obtains through superior talents for business, or superior business arrangements, are very much of a similar kind. If all his competitors had the same advantages, and used them, the benefit would be transferred to their customers, through the diminished value of the article: he only retains it for himself ​because he is able to bring his commodity to market at a lower cost, while its value is determined by a higher. All advantages, in fact, which one competitor has over another, whether natural or acquired, whether personal or the result of social arrangements, bring the commodity, so far, into the Third Class, and assimilate the possessor of the advantage to a receiver of rent. Wages and profits represent the universal elements in production, while rent maybe taken to represent the differential and peculiar: any difference in favour of certain producers, or in favour of production in certain circumstances, being the source of a gain, which, though not called rent unless paid periodically by one person to another, is governed by laws entirely the same with it. The price paid for a differential advantage in producing a commodity, cannot enter into the general cost of production of the commodity.
A commodity may no doubt, in some contingencies, yield a rent even under the most disadvantageous circumstances of its production: but only when it is, for the time, in the condition of those commodities which are absolutely limited in supply, and is therefore selling at a scarcity value; which never is, nor has been, nor can be, a permanent condition of any of the great rent-yielding commodities: unless through their approaching exhaustion, if they are mineral products (coal for example), or through an increase of population, continuing after a further increase of production becomes impossible: a contingency, which the almost inevitable progress of human culture and improvement in the long interval which has first to elapse, forbids us to consider as probable.