728 PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 28

nifies that the value of the services rendered by capital goods
is the total of the amortization of all capital goods and the
interest on their global value.
Thus, in the present theory, the value of a privately owned
and used motor car is not counted in income Rec at the moment
 of sale to its owner. This value appears in the form of
income only in the form of the services rendered by the car
over time. The definitions usually adopted, by contrast, include
the value of an automobile in R’; at the moment of sale.
There is no difficulty in specifying the correction to be made
to Rc to derive Rg, at least as a first approximation.
The adjustment consists of subtracting investment in consumer
 durables Ic from consumed income R”c as it is normally
calculated, and adding back the amortisation of consumer
durables Ac and the interest {Cy chargeable against the capital
represented by existing consumer durables Co (1).
Thus

Re=R"- Ic + Ac +ICo ,

Now, from the definition of amortization

d Ce
Ac=le-=1lc-

 Pc Ce

!) Relation (116-2) above.

11] Allais - pag. 32