SEMAINE D'ÉTUDE SUR LE ROLE DE L'ANALYSE ECONOMETRIQUE ETC. 501

We might say that there is also another stock in the system,
at the beginning of the period we are considering, namely population.
 This stock, however, for economic purposes, is not
relevant as such, i.e. as a stock (except in a slave society,
which is outside our interests). Its economic relevance is connected
 only with the flows it calls into being.
Let us come, therefore, to consider these flows. As in the
previous case, all the members of the community are grouped in
a final sector #. This final sector provides the labour services
to all productive processes and owns the stocks of capital.
Moreover, it exerts the demand for all the final goods, which
are now of two types — consumption goods and investment
goods.

The flows of consumption goods, as before, come from
‘n — 1) consumption goods sectors. In addition to these, we
have now a whole series of flows of investment goods, which
will be denoted with the suffix k. As a first step to the more
general formulation of section 7, we shall assume that capital
is required only for the production of consumption goods, while
capital goods can be produced exclusively from labour. Since
the unit of measure of capital is different for each consumption
good sector, the process for the production of capital goods
must itself be expanded into (# - 1) sectors. Our system thereby
 acquires (z - 1) new variables: Xp,o Xi,» oor Xi,» cach
of which represents the production of capital for the corresponding
 consumption goods sector. This production of capital goods
s devoted partly to new investment (expressed by demand
coefficients in the final sector: a, ; ns Ayn, @ ,) and partly
‘0 replacement of worn-out capacity (expressed by replacement
coefficients : Ak,1> 4,2 +++» @p,_,n-1)- Hence the whole struccure
 of physical flows can be represented by the following
system of equations, which takes the place of (II):

10] Pasinetti - pag. 21