SEMAINE D’ETUDE SUR LE ROLE DE L’ANALYSE ECONOMETRIQUE ETC. 64y

These relations define equilibrium investment in each single
sector, and therefore their sum defines total equilibrium investnents
 in the system as a whole. As can be clearly seen, equilibrium
 investments, in physical terms, are exclusively deter
mined by the expansion of demand.
Yet, as we know, the actual undertaking of all these investments
 only provides the required productive capacity, i.e. potential
 full employment. For the system to reach full employment,
 a further macro-economic condition about total effective
demand must also be satisfied.
In mathematical terms, all this is expressed by the fact
‘hat conditions (V.g) only come to complete the two systems
of equations (II.g) and (II.13), by defining at any point of
ime the series of coefficients (demand coefficients for new investments)
 which was still missing. But the two systems of
equations, thus completed, are of the linear and homogeneous
type, and their coefficient matrix must be singular if they are
‘o yield non-trivial solutions. This condition of singularity,
which was expressed by (II.20) with reference to a particular
period of time, must now be kept satisfied over time. After
substituting (V.q) into (II.20) and after explicitly expressing
‘he movements of the coefficients. we obtain

V.11)

1,,(-0) a, (1-9) eri—ed.

+247.) apai-0) a, (1-9) erro

Pl

which finally represents, under our present hypotheses, the
effective demand condition for keeping full emplovment over
time. …
This expression, as pointed out earlier, refers to the ecoaomic
 system as a whole. The effect of substituting into it
sxpressions (V.q) is that now (V.11), besides stating the general

[10] Pasinett: - pag. 79