[44] "De Justitia et Jure," d. 4, a. 1.
[45] "Summa Theologica," 2a 2ae, q. 57, a. 2 and 3.
[46] "De Justitia et Jure," d. 6, s. 1, n. 6.
[47] The assumption that perfect competition is even roughly approximated in relation to men who operate their own land, and that they generally obtain an adequate return for their labour in addition to the sum that they might have obtained through hiring out their land, may appear rather violent in view of the estimate that the average farmer in the United States gets only $402 annually in payment for the labour of himself and family. See article on "The Farmer's Income" in the American Economic Review, March, 1916. However, this income is mostly in the form of food, fuel, and shelter, which would cost very much more in the city; consequently it is probably equivalent to an urban income of $600. Its value is still further enhanced by the farmer's independent position, and by his expectation of profiting by the future increase of land values. Hence it would seem that the rent and interest allowance of $322 might fairly be regarded as a surplus in excess of the necessary payment for labour.
[48] Chapter xxii.
[49] "Report of the Commissioner of Corporations on the Petroleum Industry," Part I, p. 8.
[50] P. 138.
[51] Cf. Ely, "Monopolies and Trusts," pp. 59, sq.
[52] P. 133.
[53] Pp. 68, 69.