Chapter 19 CHAPTER III THE FERTILITY OF THE LAND (Continued) Tendency to Diminishing Returns

CHAPTER III THE FERTILITY OF THE LAND (Continued) Tendency to Diminishing Returns Section 1. The land may be undercultivated, so that the returns due to the increase of capital and labor will increase until a maximum rate of return is reached, after which the returns will decrease again.Improvements in the methods of cultivation may render more capital and labor more profitablely employed.The law of diminishing returns is about the quantity of a product, not about its value. The statement of law of diminishing returns or propensity for diminishing returns can be tentatively stated as follows:

Increases in the capital and labor employed in the cultivation of the land generally produce a proportionally lower increase in the quantity of agricultural produce obtained, unless by coincidence coincident improvements in the art of agriculture occur. We know from history and observation that every peasant in all ages and places wishes to use a great deal of land;If he thinks that all his capital and labor can be employed with as good results on a small piece of land as on a large one, he will pay nothing but this small piece of land. buy other land. When land that does not need to be cultivated can be acquired at no cost, each man employs only that amount of land which he thinks will give the greatest return to his capital and labour.

His farming is "extensive farming" rather than "intensive farming".It is not his object to get a great deal of corn from an acre of land, since, if that were the case, he would need only till a few acres.His object was to obtain as much of the whole harvest as possible at the expense of a given amount of seed and labor; he therefore sowed as many acres as he could manage under extensive cultivation.He may, of course, go too far: the area he cultivates may be so large that it is advantageous to concentrate capital and labor on a smaller area; In order to use more of each acre, the land would pay him a diminishing return; that is to say, the return would increase in proportion to what it would give him for his present expense.But if his calculations are correct, he employs just that much land to give him the greatest return; and he would suffer a loss if he had concentrated his capital and labor on a smaller area.If he has more capital and labor at his disposal and uses more of the land he has, he will be less profitable than he would be by cultivating more land, and he will receive a diminishing return; that is to say, The increase in remuneration is proportionally less than what he would now have received for his capital and labor at last employed, assuming, of course, that at the same time there has been no appreciable improvement in his agricultural technique.When his sons are older, they will have more capital and labor to employ in the land; and in order to avoid diminishing returns, they will cultivate more land.But perhaps by then all the neighboring lands will have been cultivated, and in order to get more land they will have to buy it, or rent it and pay rent, or move where they can get it for free. .

The tendency for diminishing returns is the reason Abram and Lot parted ways, and the reason for most of what history says is immigration.Wherever the right to cultivation is very much needed, we may trust that the tendency to diminishing returns is in full operation. If it were not for this tendency, every farmer would save almost the whole rent by giving up all but his small plot of land and devoting all his capital and labor to it.In this case, if all the capital and labor which he employs in this little land yields in proportion as much as the capital and labor which he now employs in it, then He would get as much produce from this little piece of land as he now gets from the whole field; net profit.

It may be admitted that the extravagance of the peasants often leads them to cultivate more land than they can properly manage: indeed, this error has been denounced by nearly every authority on agriculture since Young.But when they tell the peasants that it is advantageous to employ their capital and labor on a smaller area, they do not necessarily mean that a greater total produce will thus be obtained.It is their argument that the savings in rent more than outweigh the possible reduction of the peasant's total return from the land.If a farmer pays a quarter of his produce as rent, suppose the increase of capital and labor which he employs per acre of land, brings him a return in proportion at least more than three-quarters, it would be advantageous for him to concentrate his capital and labor on a lesser amount of land.

Next, Even in a country as advanced as England, there is still much land so unskilled in cultivation that, if employed twice as skilfully as present capital and labor, the total produce of these lands would It can be more than double, which is also admitted.Those who maintain that if all the English farmers were as able, intelligent, and energetic as the best farmers, they would advantageously use twice as much capital and labor as they do now, are probably right.Assuming that rent was a quarter of the present produce, they would increase to seven hundredweights for every four hundredweights of their present produce: and it is conceivable that, with more improved methods of cultivation, they would obtain eight hundredweights, or even More.However, considering the status quo, this does not prove that more capital and labor can be used to obtain increasing returns from land.The fact is this: We take peasants as they are now, and with all the skill and energy they actually possess, and our general observation is that even if they give up most of the land and concentrate all their capital and labor on the remaining land, Except for the land rent of this part of the land, the saved land rent belongs to themselves, and there is no shortcut for them to get rich.The reason why they cannot do this is because of the law of diminishing returns, which, as has been said, is measured by its quantity, not by its exchange value.

We can now clearly state the limitations implied by the words "generally" in the provisional statement above about the law of diminishing returns.The law of diminishing returns is the statement of a tendency which, it is true, may be temporarily retarded by the intermittent process of improving the technique of production and developing the full potential of the soil; but if the demand for produce increases without limit, this This tendency must eventually become irresistible.Our account of this tendency can be divided into the following two parts: Though improvements in the art of agriculture may increase the rate of return which land normally affords for a given quantity of capital and labor; Even with the present technique of agriculture a more than proportional return may be obtained; but such cases are rare in an ancient country: besides the existence of this, the increase of capital and labor employed in the land, The increase in the quantity of produce obtained is proportionately lower, unless there is also an increase in the skill of the individual cultivator.Second, no matter what the future development of agricultural technology is, the continuous increase of capital and labor used in land will eventually inevitably lead to a diminishing increase in the amount of product that can be obtained by adding a certain amount of capital and labor.

Section II A dose of capital and labor.Marginal agents, marginal rewards, farming margins.A marginal dose is not necessarily the last dose in time.Surplus produce; its relation to ground rent.Ricardo's attention is limited to the case of an ancient country. Using a term introduced by James Mill, we may regard the capital and labor employed in the land as consisting of equal quantities of successively employed agents.We have seen that the rewards from the first few doses may be small, and that many subsequent doses may yield greater than proportional rewards; that in exceptional cases the rewards from successive doses may even alternate. Time increases and time decreases.But, according to the law of diminishing returns, sooner or later (always assuming no concomitant change in the technique of cultivation) a certain point is reached after which all additional doses produce returns proportionally less than The rewards generated by previous doses.This dose always refers to the combined dose of labor and capital, whether employed by the yeoman who cultivates his land alone, or by the agricultural capitalist who does not cultivate himself.In the latter case, however, the subject of the cost is in the form of money; in the study of the economy of agricultural operations in relation to the situation in England, the conversion of labor into monetary equivalents according to market value is considered, and we speak of capital rather than capital. Labor and capital are often convenient.

A dose which just covers the expense of the cultivator may be called a marginal dose, and the remuneration it produces may be called a marginal return.If there happens to be cultivated land nearby, but this land barely pays for its expense, and leaves no surplus for rent, we may regard the use of this land as a marginal agent.Thus we may say, with the advantage of simplicity, that the dose applied to the land is applied to the land at the margin of cultivation.But this argument does not need to assume the existence of such land: all we are concerned with is the return produced by the marginal agent, and it does not matter whether it is used in barren or fertile land; all that is necessary is that it should be able to The last dose is advantageously used on land on the margins of cultivation.

When we speak of a marginal or "final" dose for land, we do not mean the last dose in time, but the one on the margin of favorable expenditure, that is, using the Just the general remuneration for the capital and labor of the cultivator, without a surplus.To take a concrete example, we may suppose that a farmer hesitates at the thought of sending mowers to the fields again to weed the fields, and decides that it makes good money, but it is only good money to do so.The dose of capital and labor expended on it, therefore, is what we call the last dose, though many doses will be employed in subsequent harvests.Of course, the reward from this last dose is inseparable from the others; but if he decides not to increase this mowing, we trust that this part will not be added to the produce, and therefore we Just use this part of the product as the last dose.

As the remuneration produced by the one dose employed at the margin of cultivation will only cover the expense of the cultivator, the sum of the marginal returns from his employment of the total number of doses will only cover his whole capital and capital. labor.If his remuneration exceeds this amount, the excess is the surplus produce of the land.If the land belongs to the cultivator himself, this surplus of produce also belongs to him. It is important to note that the above statement of the nature of the surplus-product is not a theory of ground-rent: we shall not speak of the theory of ground-rent until a later stage.All that can be said here is that, under certain conditions, this surplus product can be converted into ground rent, which the landowner can impose on the tenant for the use of his land.But, as we shall hereafter see, the complete rent of the land of an ancient country consists of three factors: first, due to the value of the soil created by nature; secondly, due to the improvements made by man; The third - and this is often the most important factor among them - is the growth of a dense and wealthy population, and the convenience of transportation such as roads and railways. Another point to be observed: In an old country it is impossible to know what the state of the land was like before it was first cultivated.The results of certain human works, whether good or bad, have been fixed in the earth and are indistinguishable from those of nature: the dividing line between the two is vague and can only be drawn more or less arbitrarily.But, for most purposes, it is best to regard the first difficulties against nature as having been fully overcome before we consider the cultivation of the peasant.Thus the remuneration produced by the doses of capital and labour, which we regard as the first employed, is generally the greatest of all remunerations, and the tendency to diminishing returns immediately manifests itself.We are chiefly concerned with English agriculture, which we may take as a typical example, as Ricardo did. Section 3 The measurement of land fertility must be related to place and time. Next, let us examine how the rate of diminishing or increasing returns from successive doses of capital and labor is determined.We have seen that there is a great difference in the part of the production which man may regard as the result of man multiplying his own work beyond what nature alone can produce; The size of this part of the produce depends largely on the crops, the soil, and the method of cultivation.Generally speaking, from forest to pasture land, from pasture land to cultivated land, from plowed land to hoed land, this part of the product is more and more, because the rate of diminishing returns is usually the largest in the forest, and smaller in the pasture land. The plowed land is smaller, and the hoed land is the smallest for the sake of it. There is no absolute measure of the fertility or fertility of the land.Even if there is no change in agricultural technique, merely an increase in the requirements of produce can reverse the ranks of fertility of two adjacent plots of land.When both lands are uncultivated, or both are equally extensively cultivated, one of them produces less; but when both are equally intensively cultivated, the one outnumbers the other, and Fairly listed as more fertile land.In other words, there is much land which is least fertile when it is only extensively cultivated, and becomes most fertile when it is intensively cultivated.For example, pasture land that can drain itself can get a relatively large return as long as it costs a small amount of capital and labor. The mixed cultivation of root vegetables, corn, and pastures will gradually become advantageous; hence the returns to the increased employment of each dose of capital and labor will not diminish as rapidly as before. There are lands which are poor as grazing land, but yield a more or less rich return to the great stock and labor employed in the cultivation and fertilization of such land; Not huge, but the returns are slowly diminishing. Furthermore, some lands are low-humidity.Such lands, like the moors of the east of England, produce nothing but wicker and game fowl.Or, as is the case in many tropical regions, the land may be lush with vegetation, but so dense with miasma that it is difficult for man to live there, and still more difficult to work.In this case the return of capital and labor, initially small, was increased by the progress of drainage; and thereafter perhaps fell again. But when this improvement has once been effected, the capital invested in the soil is immobilized; the history of the first days of cultivation is not repeated; and there is a tendency for diminishing returns to increase the produce obtained from the employment of capital and labour. A similar, though less marked, change would take place in land already well cultivated.For example, land that isn't low in humidity may need a little drainage work to drain standing water and allow fresh water and air to flow.Alternatively, the underlying soil may happen to be naturally more fertile than the surface soil: or the underlying soil may not be very fertile, but may have just those qualities that the surface soil lacks, so thorough deep plowing with steam plows, The nature of the land can be permanently changed. Thus we need not think of ever-continuously diminishing returns when increased capital and labor begin to produce diminishing returns.Improvements in the art of production - as we have always understood them - generally increase the remuneration which any amount of capital and labor can produce; but that is not what is being said here.What is said here is this: Leaving aside any increase in the knowledge of the farmer, he uses only those methods with which he is already familiar, and if the capital and labor at his disposal increase, even at a later stage of his cultivation, he sometimes Incremental rewards are available. ②As the strength of a chain is the strength of its weakest link, so it is true that the fertility of the earth is limited by its least element.Those who are in a hurry do not use a chain which has one or two weak links, however strong the rest may be: prefer a much thinner chain which is free from fault.But if heavy work is to be done, and they have time to make repairs, they fix the larger chain so that its strength exceeds that of the other.This fact can be used to explain many seemingly strange events in the history of agriculture. The first settlers in a new country generally do not want land unsuitable for immediate cultivation.They are often repelled by the abundance of native plants, if they happen to be not the kind they want.No matter how fertile the land may become with careful cultivation, they will not cultivate it if it is difficult to cultivate.They don't even cultivate land with a lot of water.They usually choose land that is easy to cultivate, which can be easily cultivated with only two plows, and then they sow widely, so that when the crops grow, they can get abundant sunlight and air, and can grow from a wide area. absorb nutrients. When the Americas were first settled, many of the agricultural work that is now done by horse-powered machinery was still done by hand; although farmers now like flat grasslands, free of broken trees and stones, and machines can be easily operated without danger, but at that time The peasants don't dislike the mountains very much.Their harvest is small in proportion to the area cultivated, but large in proportion to the capital and labor employed in raising the crop. Until, therefore, we know something about the skill and enterprise of the cultivator, and the amount of capital and labor at his disposal, and whether the wants of the produce make it advantageous for him to cultivate intensively with the resources he has, We can say that one piece of land is more fertile than another.If the demand for produce favors intensive cultivation, the land which gives the greatest average return to a great deal of capital and labor is the most fertile; , is the most fertile land.The term fertility has no meaning except in relation to particular circumstances of a definite time and place. But even with this restriction, there is some ambiguity in the usage of the noun.Attention is sometimes chiefly to the power of the land to produce an adequate return to intensive cultivation, and to produce a great total produce per acre; The total produce of the country is not very great: for example, the present abundant arable land in England is very fertile in the former sense, and pasture land is fertile in the latter sense.For many purposes it does not matter which sense the term is taken in: but in a few cases it does, so that there must be a statement of interpretation in the context. Section IV Because of the increase of population pressure, the value of barren land is usually relatively higher than that of fertile land. But, to go a step further, the degrees of fertility of the various soils are liable to be varied by variations in the method of cultivation, and in the relative value of the various crops.For instance, when, towards the end of the last century, Mr. Coke showed how, by first planting clover, wheat would grow well on easy soil, so that the value of easy land was relatively greater than that of sticky soil; Though cultivated land is sometimes still customarily called "barren" land, there is a part of it which, if left to itself, is of higher value, and indeed more fertile, than much land which has been carefully cultivated. Next, the increasing demand in Central Europe for timber for fuel and building material has increased the value of pine-wooded hillsides relatively to that of almost other kinds of land.But in England, by the substitution of coal for fuel, and iron for shipbuilding, and by the peculiar convenience of importing timber from England, the increase in the value of hillside land is hindered.Again, the cultivation of rice and jute tends to give a high value to land which is too watered to support most other crops.Again, since the abolition of the Corn Acts, the price of meat and milk in England has risen relatively more than that of corn.For example, the value of arable land rich in forage crops, which can be grown in rotation with grain, increases relatively compared with cold sticky land; the value of permanent pasture land decreases greatly compared with arable land, but due to the increase in population, the value of this decrease has already been reduced. Some have recovered. Leaving aside any variations in the general crops and methods of cultivation which are suited to particular soils, there is a constant tendency to equalize the values ​​of all kinds of land.The increase of population and wealth, absent any special cause to the contrary, would bring the barren land to the value of the fertile land.Soil, once quite neglected, may, by the labor invested in it, produce abundant crops; it receives probably as much sunlight, heat, and air in a year as fertile ground: and its defects can be greatly amplified by labor. reduce. Just as there is no absolute criterion for the fertility of the soil, there is no absolute criterion for good farming.The best cultivation of the most fertile parts of the Channel Islands, for example, costs an enormous amount of capital and labor per acre: for these are near a great market, and are blessed with an unvarying and early ripening climate.If left to its own devices, the soil there would not be very fertile because, for all its advantages, it also has two weak points (lack of phosphoric acid and potassium carbonate).But, partly by the aid of the rich seaweeds of its shores, these two weak links are strengthened, and the chain becomes very strong.Thus intensive cultivation - or "good" cultivation, as it is commonly called in England - will produce early potatoes worth a hundred pounds per acre.But the farmer in the American West would have been bankrupt if he had spent the same amount per acre; and in his case intensive cultivation was not good but bad cultivation. Section 5 Ricardo once said that the most fertile land is cultivated first; in the sense he said this, it is true.However, he underestimated the indirect benefits that dense populations provided to agriculture. Ricardo's statement of the law of diminishing returns is imprecise.This inaccuracy, however, is probably not due to an oversight of thought, but only of phraseology.At any rate, given the particular circumstances of England at the time he was writing, and for the particular purpose of some of the practical problems he had in mind, it is presumably unquestionable that he does not consider the situation of diminishing returns to be of great importance. .Of course he would not have expected many inventions which would open up new sources of supply and, with the help of free trade, revolutionize English agriculture; Special emphasis is placed on the possibility of some kind of change. He said that the first settlers in a new country must choose the most fertile land, because the increase of population gradually cultivated the more and more poor lands, he said so casually, as if the fertility of the land had increased. Absolutely the same standard.But we have seen that, where land is available at no cost, each chooses that which is best suited to his own purpose, and which, all things considered, will give the best return for his capital and labor.He therefore looks for land which can be cultivated immediately, ignoring land in which there is any weak link, however strong the other links may be, in the chain of the factors of fertility.But besides having to avoid the miasma, he must consider his communications with markets and resource bases, and in some cases the need for security against the attacks of enemies and wild beasts outweighs all other concerns.We cannot, therefore, expect that the land first chosen will often be the one which is at last regarded as the most fertile.Ricardo did not take this into account, and he was attacked by Carlyle and others, although much of this attack was based on a misunderstanding of Ricardo's insights, but there was something real in it. The fact that in the new country the land which the English farmer regarded as barren was sometimes cultivated before the adjacent land which he regarded as fertile was not, as some foreign writers believed it to be, contrary to Ricardo's doctrine. The gist is contradictory.The practical importance of this fact has to do with the conditions under which an increase in population tends to bring about an increased pressure on the means of subsistence; an importance which shifts the focus of research interest from merely the quantity of the peasant's produce Transferred to it is the exchange value expressed in what is offered in exchange for agricultural produce by the industrial population adjacent to the peasantry. The sixth section continues. Ricardo and his contemporaries drew this inference from the law of diminishing returns, generally too hastily; they did not take adequate account of the increase in organizational power.But in fact, every farmer has neighbors— Whether you're a farmer or a town resident—and get help.Even if most of his neighbors were like him in agriculture, they gradually provided him with good roads and other means of communication: they also gave him a market where he could buy what he wanted at reasonable terms, Necessaries, comforts, and luxuries for himself and his household, and every sort of agricultural necessity.They gave him knowledge: they gave him medical, educational, and recreational facilities; his mind was broadened, his efficiency in many ways increased.His interest is still greater if the nearby town expands into a great industrial centre.All his produce was worth more; some things he had been accustomed to throw away fetched a good price.In pasture and gardening he was given new opportunities, and as the range of produce increased, he adopted the method of rotation, keeping his land always available, without losing any of what was necessary for its fertility. ingredients. There is a further layer, as we shall see later, that an increase in population tends to develop the organization of trade and industry; and therefore the law of diminishing returns does not apply to all capital and labor expended in one area as it does to all capital and labor expended on a field. All capital and labor are as definite.Even when cultivation has attained a stage after which each successive dose of stock and labor employed in the field yields a less return than the preceding dose, it may be possible for an increase in population to increase the means of subsistence more than proportionately. .It is true that the bad day is but a postponement: but it is a postponement.The growth of population, if it is not hindered by other causes, must at last be hindered by the difficulty of obtaining agricultural produce; but, notwithstanding the law of diminishing returns, the pressure of population on the means of subsistence can, for a long time, be sufficient for the development of The new range of supplies, the cheapness of rail and steamship transportation, and the advances in organization and knowledge held back. Contrary to the above, it must be that in densely populated places the difficulty of obtaining fresh air and sunlight and—in some cases—fresh water increases.The natural beauty of places of interest has an immediate monetary value that cannot be ignored; however, some effort is needed to realize the true value of being able to enjoy a variety of beautiful landscapes for men, women and children. The seventh section is the law of remuneration for fishing grounds, mines and construction land. As mentioned earlier, land in economics terms includes rivers and oceans.In river fishing, the increased remuneration of the increased employment of capital and labour, exhibits a sharp diminishing decline.As for marine fishing, opinions are divided.The oceans are large in volume and very rich in fish; some argue that humans can draw a virtually unlimited supply from the oceans without significantly affecting the number of fish remaining in the oceans; or in other words, diminishing returns The same law is almost inapplicable to ocean fishing: meanwhile, others argue that the productivity of a fishery that is struggling to catch, especially with steam trawlers, is reduced.This question is important because the future world population will be significantly affected, both quantitatively and qualitatively, by the available fish supply. The produce of mines—quarries and brickyards are counted among mines— It is also said to be in accordance with the law of diminishing returns; but this is misleading.We shall have increasing difficulties in obtaining a further supply of minerals, except that we shall have greater control over natural deposits only by means of improvements in mining technology, and of knowledge of the contents of the earth's crust. This is true; and there can be no doubt that, other things being equal, the continual employment of capital and labor in mines results in a diminishing rate of produce.This product, however, is not a pure product like the remuneration we speak of in the law of diminishing returns.That remuneration is part of a continually recurring revenue, and the produce of a mine is but a part withdrawn from its store of wealth.The produce of the field is something other than the earth; for the field, when properly cultivated, retains its fertility.But the produce of a mine is a part of the mine itself. This question can also be explained in another way.The supply of agricultural products and fish is a continuous stream, while minerals are like natural reservoirs.The closer the cistern is to dryness, the greater the labor involved in pumping water from it; but if one man can pump the water out of the pool in ten days, ten people can do it in one day: There will be no more water in the pool.A mine that is being worked this year may therefore be as easy to work as it was many years ago: ten years' supply of coal, if properly planned in advance and prepared with the special capital and skill required for the work, can be produced. It can be mined in a year without any difficulty; but once a mine has been opened it can produce no more.This difference is also explained by the fact that the rent of mines and the rent of fields are calculated on different principles.A tenant farmer can stipulate in the contract to return the same fertile land as before: but the mining company cannot do this; the land rent of the tenant farmer is calculated on a yearly basis, while the ground rent of the mine is mainly composed of "rental fees", which rent Fees are levied in proportion to the goods withdrawn from the reserves of nature. On the other hand, the earth, in giving man space, sunlight, and air— With them humans can live and work—services rendered, indeed, strictly in accordance with the law of diminishing returns.It is advantageous to have an ever-increasing capital employed in lands of special interest in position—natural or artificial.Buildings soar into the sky; natural light and ventilation are supplemented by artificial means, and the elevator reduces the inconvenience of the uppermost floors of the house; to this expenditure the reward for convenience increases, but it is a diminishing one.No matter how high the land rent for building land is, it will eventually reach a certain limit. Beyond this limit, it is better to pay more land rent to use a larger area than to build up layer by layer; just as farmers know that in the end There must always be a stage beyond which further intensive cultivation cannot offset the expenditure. Instead of using more capital and labor on the original land and getting diminishing returns, it is better to pay more land rent to use larger land. Same.From this we can see that the theory of land rent is essentially the same as that of field rent.This and similar facts now enable us to simplify and develop the theory of value advanced by Ricardo and Mill. This is true for building land, as it is for many other things.If a manufacturer has (say) three planing machines, he has no difficulty in getting a certain amount of work from them.If he was to get more work from them, he would have to try to save not a single minute of their operation during normal working hours, and perhaps work overtime.Thus, once they have been fully utilized, he is rewarded with diminishing returns for each successive exertion of force upon them.In the end, the net remuneration was so small that he found it more profitable to buy a fourth machine than to force his old machine to do much work: just as a farmer who has fully cultivated his It is not as profitable to buy more land to produce more products from the existing land.诚然，从某些观点来看，从机械所得到的收入多少带有一点地租的性质：在第五篇中再加说明。 第八节报酬递减律和一剂资本和劳动的注释。 在这里我们不能充分考虑报酬递减概念的伸缩性；因为，这个概念不过是在投资方面关于资源之经济的分配之大的一般问题中的一个重要的细节而已，而这一问题是第五篇的主要论述之中心，实在也是全书大部分的中心。但是，关于这个概念，现在在这里似乎需要略加说明，因为在卡尔教授的有力和有启发性的倡导下，近来对这个概念极为重视。 如果一个制造商将他的资本用于机械方面为数过大，以致有很大一部分机械经常空着不用；或者用于建筑物方面为数过大，以致有很大一部分的地方没有充分使用；或者用于雇用职员方面为数过大，以致所用的职员中一定有一部分人的工作抵不过付给他们的工资；因此，在这一方面他的过度的支出，就不像以前的支出那样有利可图了，所以我们可以说，这种支出对他产生了“递减的报酬”。但是，这个名词这样的用法，虽然极其正确，但除非谨慎使用，否则就容易令人误解。因为，当用于土地的劳动和资本的增加所产生的报酬递减倾向，是被看作任何生产要素，在与其他要素的比例上用得过多时所产生的一般报酬递减倾向的一个特殊的例证时，人们就易于认为，其他生产要素的供给是能够增加的。这就是说，人们易于否认在一个古老国家中现有的全部可耕土地的固定性这个条件的存在，而这个条件是我们刚才考虑的关于报酬递减律之重要的古典研究之主要基础。即使当个别农民要在靠近他自己田地的地方增加十英亩或五十英亩土地时，除了能出高到令人不敢过问的价格，否则恐怕总不能得到它们。即使从个人观点来看，在这方面土地也是与其他大多数生产要素不同的。这种差别对于个别农民，诚然可看作是没有多大关系。但是，从社会的观点，从以下关于人口各章的观点来看，这种差别却是重要的。让我们就来研究这个问题。 在任何生产部门的每个方面，都要将资财分配于各种支出，而某种分配的办法能比其他任何分配办法产生较好的结果。管理企业的人越能干，他就越接近十分完美的分配；正像管理一个家庭所有的羊毛之原始社会的主妇越能干，她就越接近羊毛在家庭的各种需要之间的理想的分配一样。 如果他的营业扩大了，他就要以适当的比例来增大各种生产要素的使用；但不是像有时所说的那样，按照比例来增大。例如，手工操作与机器操作的比例，在一家小的家具厂里也许是适当的，而在一家大的家具厂里，这一比例恐怕就不适当了。如果他对他的资财的分配做到尽可能的适当，他就从他的各种生产资料中得到他的企业所能得到的最大（边际）报酬。如果他使用任何一种生产资料过多，他就从这种生产资料中得到递减的报酬；因为其他生产资料与它不能适当配合。这种递减报酬与农民所得到的递减报酬是相同的，如果农民对土地如此地精耕，以致从土地获得递减的报酬。倘使农民能以与付给原来土地的相同的地租而获得更多的土地，他就会租用更多土地，否则，他就会受到责难，被看作是一个无能的经营者；这就说明了以下的事实：从个别耕作者的观点来看，土地不过是资本的一种形态而已。 但是，前代的经济学家说到报酬递减律时，他们不但从个别耕作者的观点，而且从整个国家的观点来研究农业问题。 现在，如果整个国家发觉它现有的刨床或耕犁为数过多或是过少，它就能重新分配它的资源。它能增加它所缺少的东西，同时逐步减少过多的东西：但对土地它却不能这样做。它对土地可以更加精耕细作，但却不能获得更多的土地。由于这个理由，前代的经济学家力言以下一点是对的：从社会观点来看，土地的地位与其他人类可以无限制地增加的生产资料的地位，不是完全相同的。 毫无疑问，在一个新的国家中，还有大量的肥沃土地未加耕种，因此，现有的全部土地之固定性是不起作用的。美国经济学家说到土地的价值或地租时，往往认为它是随着土地与良好市场的距离而不同的，而不是随着土地的肥力而不同；因为，即使现在，在美国还有许多肥沃的土地未被充分耕作。同样地，他们不大重视下一事实：在像英国那样的国家里，谨慎的农民用于土地的劳动和资本一般所产生的递减报酬，与不谨慎的农民或制造商对数量过多的耕犁或刨床不适当的投资所产生的递减报酬，不是处于完全相同的地位。 当报酬递减倾向变为普遍时，报酬易于以价值，而不是以数量来表示，这是确实的。然而，必须承认这一点：用数量来衡量报酬的老方法，往往碰到没有货币衡量的帮助就不能正确解释一剂劳动和资本的困难；而且，这个方法虽有助于广泛的初步衡量，但不能供深入研究之用。 但是，如果我们要把往昔的或远处的土地之生产力都纳入一个共同的标准，即使采用货币衡量的方法也无济于事。因此，我们必须重新采用概略的、多少是武断的测量方法，这种方法不是以数字的标准为目的，但仍足供广泛的历史研究之用。我们必须考虑以下这些事实：一剂中的劳动和资本的相对数额有很大不同；资本利息这个项目，通常远不及在农业的进步阶段那样重要，虽然利率在后一阶段一般是低得多了。为了大多数的目的，以具有一定效率的一天的不熟练劳动作为共同标准，大概最为妥当：这样，我们认为一剂是由一定数量的各种劳动，和资本的使用及偿还的一定费用所构成的，而合在一起就等于十天（比如说）这样的劳动之价值； 这些因素的相对比例，和以这样的劳动表示的它们个别的价值，是按照每个问题的特殊情况来确定的。 对于在不同情况下使用劳动和资本所得到的报酬加以比较，也有类似的困难。只要作物属于同一种类，一种报酬的数量就能与另一种报酬的数量比较：但是，如果作物属于不同的种类，则要把它们化为一个共同的价值尺度之后，才能比较。例如，当我们说到土地对某种作物或某种作物轮种，比对另种作物或另种轮种，能使用于土地的资本和劳动产生较好的报酬时，我们必须理解，这样讲法只是以当时的价格为基础才是对的。在这样的情况下，我们必须把整个轮种时期合在一起计算，并假定在轮种之初与轮种之末土地的状况是相同的，一方面计算在整个轮种时期所用的一切资本和劳动，另一方面计算一切作物的总收获。 我们必须记住，一剂劳动和资本所产生的报酬，在这里不是被当作包括资本本身的价值在内。例如，如果用于田地的资本的一部分是由两岁的牡牛若干头构成的，则一年的劳动和资本所产生的报酬，并不是包括年终这些牡牛的全部重量在内，而只包括这一年内所增加的重量。又如，当我们说到一个农民耕种土地的资本是十镑时，这十镑包括他的田地所有的一切东西的价值在内；但是，一年（比如说）之中用于田地的各剂劳动和资本的总数，并不包括像机械和马达这样的固定资本的全部价值在内，而只包括扣除了利息、折旧和修理费用之后的它们的使用价值，虽然这一总数的确包括像种子这样的流通资本的全部价值在内。 以上所述是一般所采用的衡量资本的方法，如果没有相反的意见，这个方法可以看作没有问题了；但是，另一种方法有时更为适当。有时对所用的一切资本说成好像都是一年之初或一年之中所用的流通资本，是便利的：在这种情况下，年终时凡是田地上的东西都是生产物的一部分。这样，幼小的家畜可以当作是一种原料，而经过一定时间将它加工成为肥壮的家畜，以供屠宰。对于农具甚至也可同样处理，年初时农具的价值当作是用于田地的一定数额的流通资本，到年终时就当作一定数额的生产物。这个办法使我们能够避免一再重复使用关于折旧等方面的假定语句，并在许多方面能省去许多话。对于具有抽象性质的一般推论——尤其这种推论是以数学方式来表达时——这个办法往往是最妥当的。 在每个人口稠密的国家里，有思想的人都必须研究报酬递减律。正如凯南教授所说，报酬递减律最初是由杜阁加以清楚说明的（见他所著《生存》第420—421页），而它的主要应用则是由李嘉图加以发展的。