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 plow, 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;