SEMAINE D'ETUDE SUR LE ROLE DE L’ANALYSE ECONOMETRIQUE ETC. 
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have noticed that there is a series of coefficients which have 
not been mentioned: the Ann’ S, namely the demand coefficients 
for new investments. The reason is that these coefficients can- 
not be specified in advance. They are themselves unknowns, 
in the present model, as they must be determined in such a 
way as to be consistent with the growing productive potential 
of the system. 
Our task is, first of all, to find out the conditions under 
which equilibrium may be maintained over time; and then to 
nvestigate the time-paths of the variables of the system. 
2. The conditions for a dynamic equilibrium 
We might begin by saying that, in order to maintain equi- 
librium over time, conditions (II.20) and (II.21), which are 
satisfied by hypothesis at time zero, must also and constantly 
be kept satisfied as time goes on. A statement of this kind, 
however, now becomes uninteresting and artificial, because 
those two conditions cease to be independent of one another, 
when time is allowed to elapse. 
If population is growing, both the supply of labour services 
and the demand for each product increase, as time goes on. 
[n order that the new labour force may find employment and 
che growing potential demand may become effective, productive 
capacity must also increase. Thus, the equilibrium conditions 
for productive capacitv in time become 
111.2) 
which simply means that there must be an increase in the pro- 
ductive capacity of each commodity, parallel to the increase 
in its demand. 
The formulation may be expressed in a more helpful way 
‘101 Pasinetti - pag. 37