To recur now to the illustration we made use of in the preceding chapter: With the margin of cultivation standing at 20, an increase in the power of production takes place, which renders the same result obtainable with one-tenth less labor. For reasons before stated, the margin of production must now be forced down, and if it rests at 18, the return to labor and capital will be the same as before, when the margin stood at 20. Whether it will be forced to 18 or be forced lower depends upon what I have called the area of productiveness which intervenes between 20 and 18. But if the confident expectation of a further increase of rents leads the land owners to demand 3 rent for 20 land, 2 for 19, and 1 for 18 land, and to withhold their land from use until these terms are complied with, the area of productiveness may be so reduced that the margin of cultivation must fall to 17 or even lower; and thus, as the result of the increase in the efficiency of labor, laborers would get less than before, while interest would be proportionately reduced, and rent would increase in greater ratio than the increase in productive power. Whether we formulate it as an extension of the margin of production, or as a carrying of the rent line beyond the margin of production, the influence of speculation in land in increasing rent is a great fact which cannot be ignored in any complete theory of the distribution of wealth in progressive countries. It is the force, evolved by material progress, which tends constantly to increase rent in a greater ratio than progress increases production, and thus constantly tends, as material progress goes on and productive power increases, to reduce wages, not merely relatively, but absolutely. It is this expansive force which, operating with great power in new countries, brings to them, seemingly long before their time, the social diseases of older countries; produces “tramps” on virgin acres, and breeds paupers on half-tilled soil. In short, the general and steady advance in land values in a progressive community necessarily produces that additional tendency to advance which is seen in the case of commodities when any general and continuous cause operates to increase their price. As, during the rapid depreciation of currency which marked the latter days of the Southern Confederacy, the fact that whatever was bought one day could be sold for a higher price the next, operated to carry up the prices of commodities even faster than the depreciation of the currency, so does the steady increase of land values, which material progress produces, operate still further to accelerate the increase. We see this secondary cause operating in full force in those manias of land speculation which mark the growth of new communities; but though these are the abnormal and occasional manifestations, it is undeniable that the cause steadily operates, with greater or less intensity, in all progressive societies.