Two men employ equal capitals—one in agriculture, the other in manufactures. That in agriculture produces a net annual value of 1200l. of which 1000l. is retained for profit, and 200l. is paid for rent; the other in manufactures produces only an annual value of 1000l. Suppose that by importation, the same quantity of corn can be obtained for commodities which cost 950l., and that, in consequence, the capital employed in agriculture is diverted to manufactures, where it can produce a value of 1000l. the net revenue of the country will be of less value, it will be reduced from 2200l. to 2000l., but there will not only be the same quantity of commodities and corn for its own consumption, but also as much addition to that quantity as 50l. would purchase, the difference between the value at which its manufactures were sold to the foreign country, and the value of the corn which was purchased from it.
Mr. Malthus says, "It has been justly observed by Adam Smith, that no equal quantity of productive labour employed in manufactures can ever occasion so great a reproduction as in agriculture." If Adam Smith speaks of value, he is correct, but if he speaks of riches, which is the important point, he is mistaken, for he has himself defined riches to consist of the necessaries, conveniences, and enjoyments of human life. One set of necessaries and conveniences admits of no comparison with another set; value in use cannot be measured by any known standard, it is differently estimated by different persons.