In accordance with our assumption, the regulating price of production falls. If it were to remain constant, = £3, then the worst soil A, which used to yield no rent with an investment of only £2½, would now yield rent without worse soil being brought under cultivation. This would have occurred due to an increase in the productivity of this soil, but only for a part of the capital, not for the original capital invested. The first £3 of production price yield 1 qr; the second yield 1 1/5; qrs; but the entire output of 2 1/5; qrs is now sold at its average price. Since the rate f productivity increases with the additional investment of capital, this presupposes an improvement. The latter may consist of a general increase in capital invested per acre (more fertiliser, more mechanised labour, etc.), or it may be that only through this additional capital it is at all possible to bring about a qualitatively different more productive investment of the capital. In both cases, the investment of £5 of capital per acre yields an output of 2 1/5 qrs, whereas the investment of one-half of this capital, i.e., £2 1/5, yields only 1 qr of produce. The produce from soil A could, regardless of transient market conditions, only continue to be sold at a higher price of production instead of at the new average price, as long as a considerable area of type A soil continued to be cultivated with a capital of only £2½ per acre. But as soon as the new relation of £5 of capital per acre, and thereby the improved management, becomes universal, the regulating price of production would have to fall to £2 8/11. The difference between the two portions of capital would disappear, and then, in fact, the cultivation of an acre of soil A with a capital of only £2½ would be abnormal, i.e., would not correspond to the new conditions of production. It would then no longer be a difference between the yields from different portions of capital invested in the same acre, but between a sufficient and an insufficient total investment of capital per acre. This shows, first of all, that insufficient capital in the hands of a large number of tenant farmers (it must be a large number, for a small number would simply be compelled to sell below their price of production) produces the same effect as a differentiation of the soils themselves in a descending line. The inferior cultivation of inferior soil increases the rent from superior soils; it may even lead to rent being yielded from better cultivated soil of equally poor quality, which would otherwise not be yielded. It shows, secondly, that differential rent, in so far as it arises from successive investments of capital in the same total area, resolves itself in reality into an average, in which the effects of the various investments of capital are no longer recognisable and distinguishable, and therefore do not result in rent being yielded from the worst soil, but rather: 1) make the average price of the total yield for, say, an acre of A, the new regulating price and 2) appear as alteration in the total quantity of capital per acre required under the new conditions for the adequate cultivation of the soil; and in which the individual successive investments of capital, as well as their respective effects, will appear indistinguishably blended together. It is exactly the same with the individual differential rents from the superior soils. In each case, they are determined by the difference between the average output from the soil in question and the output from the worst soil at the increased capital investment — which has now become normal.