716 PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 28 
saucepans which will finally be bought by consumers for their 
own use. 
A part of the wage bill generated in the construction of the 
blast furnace will finally be incorporated in the price of the 
saucepan; it will thus appear, with some time lag, in national 
income. 
It can be seen that consumed national income will at a given 
time include wage outlays which were made at an earlier time, 
and, at least in theory, it is possible to consider a curve which 
specifies the distance from the present of various earlier outlays 
(wages and rents) which appear in the consumed national in- 
come of the time # considered. This curve can be called the 
« characteristic curve » of the capitalistic process under study. 
If there is a Paretian optimum, factor income is imputed 
proportionally to the marginal productivities considered in 
terms of physical values (1). 
In parallel with the characteristic curve which defines the 
origin of the different elements of primary income appearing 
in the consumed income of time #, an amortisation curve can 
be defined which represents the time distribution of the primary 
-ncome of time # over the various subsequent periods (>. 
The term Ru (2) will be used to represent the global amount 
of primary income per unit of time preceding # which is incor- 
porated in total consumed national income R_(#) of time #. The 
global amount of primary income per unit of time at time ? 
(') This imputation generates a number of very interesting problems 
which considerations of space preclude me from discussing. On this ques- 
tion, see in particular my Treatise on Pure Economic Theory (1943) and 
my Cambridge paper (1963): Some Analytical and Practical Aspects of the 
Theory of Capital. Appendix I. See also ALLAIS (1961 - C), The Definition 
of Characteristic Fonctions and the Problem of Imputation (La définition 
des fonctions caractéristiques et le problème de l’imputation). 
() In general, the definition of these two curves results from the way 
in which the accounting of imputations is undertaken in practice. If a 
Paretian optimum obtains. these imputations satisfv the corresponding 
conditions 
11] Allaic - pag. 20