Secondly, I shall endeavour to shew what are the circumstances which naturally determine the rate of profit; and in what manner, too, those circumstances are affected by the like variations in the state of the society.
Though pecuniary wages and profit are very different in the different employments of labour and stock; yet a certain proportion seems commonly to take place between both the pecuniary wages in all the different employments of labour, and the pecuniary profits in all the different employments of stock. This proportion, it will appear hereafter, depends partly upon the nature of the different employments, and partly upon the different laws and policy of the society in which they are carried on. But though in many respects dependent upon the laws and policy, this proportion seems to be little affected by the riches or poverty of that society, by its advancing, stationary, or declining condition, but to remain the same, or very nearly the same, in all those different states. I shall, in the third place, endeavour to explain all the different circumstances which regulate this proportion.
In the fourth and last place, I shall endeavour to shew what are the circumstances which regulate the rent of land, and which either raise or lower the real price of all the different substances which it produces.