[323] The illustration as given by Ricardo is somewhat more complicated.
[324] “When land of an inferior quality is taken into cultivation the exchangeable value of raw produce will rise because more labour is required to produce it.” (Ibid., p. 49.)
[325] See Cannan’s delightful volume The Theories of Production and Distribution, p. 150, where the average decennial price works out as follows:
| s. | d. | |
|---|---|---|
| 1770-1779 | 45 | 0 |
| 1780-1789 | 45 | 9 |
| 1790-1799 | 55 | 11 |
| 1800-1809 | 82 | 2 |
| 1810-1813 | 106 | 2 |
[326] The number of Enclosure Acts which Parliament, acting with the sanction of public opinion, passed during the latter part of the eighteenth and the beginning of the nineteenth centuries increased very rapidly. Between 1700 and 1845 no fewer than 3835 such Acts were passed, involving the enclosure of 7,622,664 acres, most of it common land. Not until 1845 do we find a change either in the attitude of public opinion or in the action of Parliament.
[327] It is not quite clear whether the high price of corn is due to the cultivation of new lands or whether this high price is the cause of the cultivation of new lands. The second interpretation appears to us to be the most natural, but it involves the abandonment of the Ricardian theory.
[328] Some critics, e.g. Fontenay, Bastiat’s disciple, suggested that land No. 4 might very well become No. 1, if, instead of being employed in the cultivation of corn, an intelligent husbandman were to put it to viticulture or rose-growing. But this is to beg the question. The law of rent implies products of the same kind, for it is this identity of quality that enables them to be sold at the same price. If bad corn-land could become good rose-growing ground, then of course it would take its place among rose-growing areas, yielding rent as soon as less fertile lands were employed for the same purpose.
[329] Turgot, Observations sur un Mémoire de M. de Saint-Péravy (Œuvres, vol. i, p. 420). “It can never be imagined that a doubling of expenditure would result in doubling the product.… It is more than probable that by gradually increasing the expenditure up to the point where nothing would be gained on the return, such items would successively become less fruitful. The earth’s fertility resembles a spring that is being pressed downwards by the addition of successive weights. If the weight is small and the spring not very flexible, the first attempts will leave no results. But when the weight is enough to overcome the first resistance then it will give to the pressure. After yielding a certain amount it will again begin to resist the extra force put upon it, and weights that formerly would have caused a depression of an inch or more will now scarcely move it by a hair’s breadth. And so the effect of additional weights will gradually diminish.
“The comparison is not very exact, but it is near enough to enable us to understand that when the earth is producing nearly all it can, a great deal of expense is necessary to obtain very little more produce.”
Turgot, with his usual perspicacity, has noted a fact which the Classical writers generally failed to perceive, namely, that at the beginning of the process of cultivation there may be a period when the return shows no signs of diminishing.