20. Profits depend on wages; wages on the supply and demand of labour, and on the cost of the labourers' necessaries (XLIX).
21. Profits will therefore rise if the last are easily produced, unless through stationariness of population demand for labour has increased (L).
22. In two lands with equal capital and equal population, but with different fertility of soil, profits would differ in favour of the more fertile (L).
23. The rate of interest is no sure indication of the rate of profits; and a low rate of interest may co-exist with a low rate of wages and a high rate of profits (LXIII).
24. Profits cannot be said to depend on 'the proportion which capital bears to labour,' for, where profits were lowest, most capital would be needed to produce a given return, and, where highest, least, in proportion (LI).
25. By a rise in the value of money it is possible (though not probable) that a reduced cost of labour, materials, and machinery might be followed by an increase instead of a reduction, in their money value (LXIII).
26. A dearth may increase profits and wealth by making labour cheap (LXIII).
27. Free trade in corn may increase the amount of profits more than a policy of Restriction may increase the amount of Rents (LXVII, cf. LXX).
28. Rent is always a transfer, and never a creation of wealth (LIII, LXVIII).
29. There cannot be two rates of profit at the same time in the same country (LXXVIII), nor under free trade could there be a very different rate in different countries, the cost of necessaries and therefore the rate of wages being brought nearly to a level, allowance being made for differences between one country and another in regard to the standard of living (LXXIX). It seems impossible that under free trade a fertile country, unless agriculture were its sole and only industry, and its capital were small, would long continue to sell its corn at the high prices of its less favoured rivals; the prices would fall to cost price (LXXX).