C. Under the former heads must be taken into the account such parts of property as have been immediately consumed and enjoyed.[146-7]
D. Interest on debt must be added only on the side of the creditor, and deducted from the income of the debtor; otherwise, error dupli. This does not apply to taxes or church dues because the subjects of a good state and members of a good church purchase thereby things which are really new and of at least equal value to the outlay. Besides, in both instances, it is necessary to calculate the number of men who live from the national income, the average amount of their indispensable wants, and the average price in money of the same, in order to determine the free national income by deducting the sum total of these average wants, estimated at this average price.[146-8] [146-9]
[146-1] Not only to compare the happiness and power of different nations with one another, but also for purposes of taxation, the profitableness and innocuousness[TN 3] of which suppose the most perfect adaptation to the income of the whole people.
[146-2] The former, in Rau, Lehrbuch, I, § 247; the latter in Hermann, 308 ff. The former mode of calculation gives us a means of judging of the comfort of the people, their control of natural forces, etc.; the second, of the relation of classes among the people. (v. Mangoldt, Grundriss, 99. V. W. L., 316 ff.) Each member of the nation produces his income only in the whole of the nation's economy. Hence Held, Die Einkommensteuer, 1872, 70, 77, would, but indeed only under very abstract fictions, construct private income from the national, and not vice versa.
[146-3] On the average degree of this increase of values in different industries, see Chaptal, De l'Industrie française, II, passim. Bolz, Gewerbekalender für, 1833, 111. No such scale can be lastingly valid, because, for instance, almost all technic progress decreases the appreciation of values through industry, and every advance made by luxury raises the claims to refined quality etc. See Hildebrand, Jahrbücher für Nat-Oek., 1863, 248 ff.
[146-4] Many items in Class D evade all calculation. Thus, for instance, the numberless cases of personal services which are enjoyed only by the doer himself; also the greater number of products (Nutzungen=usufruct) of capital in use for the consumption of the owner himself. (Latent income.) Only, it may be, in the case of dwelling houses, equipages, etc., that the consumption by use can be estimated in accordance with the analogy of similarly rented goods.
[146-5] The principal materials consumed in manufactures are of course not to be deducted here, because the increase in their value was taken into account above.
[146-6] When an artist who earns $10,000 per annum appears in a country, the gross national income increases in a way similar to that in which it increases when a new commodity is found which would have a yearly increase of value equal to $10,000 over and above that of the raw material. Cost of production in the case of such a virtuoso is scarcely to be alluded to. Nearly his entire income, with the exception of his traveling expenses, etc., is net, and the greater portion of it free. An income tax would affect his hearers after as it did before, and in his income, find a completely new object. Per contra, see Saggi economici, I, 176 f.
[146-7] For purposes of taxation, where a relative valuation is more the question than an absolute one, it would be sufficient to assume that every household consumed clothing, utensils, etc., in proportion to the rest of their income. Hence, these items might, unhesitatingly, be omitted altogether.
[146-8] Mathematically demonstrated by Fuoco, Saggi economici, II, 102 ff.