Another cause of the rise of rent, according to Mr. Malthus, is "such agricultural improvements, or such increase of exertions, as will diminish the number of labourers necessary to produce a given effect." This would not raise the value of the whole produce, and would therefore not increase rent. It would rather have a contrary tendency, it would lower rent; for if in consequence of these improvements, the actual quantity of food required could be furnished either with fewer hands, or with a less quantity of land, the price of raw produce would fall, and capital would be withdrawn from the land.[56] Nothing can raise rent, but a demand for new land of an inferior quality, or some cause which shall occasion an alteration in the relative fertility of the land already under cultivation.[57] Improvements in agriculture, and in the division of labour, are common to all land; they increase the absolute quantity of raw produce obtained from each, but probably do not much disturb the relative proportions which before existed between them. Mr. Malthus has justly commented on an error of Adam Smith, and says, "the substance of his (Dr. Smith's) argument is, that corn is of so peculiar a nature, that its real price cannot be raised by an increase of its money price; and that, as it is clearly an increase of real price alone, which can encourage its production, the rise of money price, occasioned by a bounty, can have no such effect." He continues: "It is by no means intended to deny the powerful influence of the price of corn upon the price of labour, on an average of a considerable number of years; but that this influence is not such as to prevent the movement of capital to, or from the land, which is the precise point in question, will be made sufficiently evident by a short inquiry into the manner in which labour is paid, and brought into the market, and by a consideration of the consequences to which the assumption of Adam Smith's proposition would inevitably lead."[58]