SEMAINE D’ETUDE SUR LE ROLE DE L’ANALYSE ECONOMETRIQUE ETC. 
659 
Here we have new problems arising because the E;’s and 
E,; 's although representing flow-variables (services from labour 
in the unit of time) come from, and are inseparably linked to, 
a stock-variable (the labour force) which may not be perfectly 
mobile. As appears from (V.16), if population is constant 
(g=0) employment in each sector ¢ increases or decreases 
through time according to whether r;>p; or r;<p;. This means 
that, on the average, half of the sectors are offering jobs and 
half of the sectors are dismissing workers, as time goes on. 
Clearly, this may be a very serious state of affairs — especially 
In a very progressive system, i.e. in a system with very high 
2s — if labour is highly specialized and is not susceptible of 
being transferred from one sector to another except at the ex 
pense of heavy losses in productivity. 
Fortunately, the natural movements of population come in 
here to help in the right direction and in two senses. First of 
all, the natural process of people ageing permits a redistribution 
sf employment among sectors by addressing young workers 
towards expanding sectors and by not replacing retired people 
in the contracting sectors. This may be a slow process, but 
it is one which is going on even when population is stationary. 
Secondly, when population is growing, its rate of increase is 
a net positive addition to the rate of change of demand (and 
herefore of employment) in all sectors. It follows that, in 
absolute terms, only those sectors will actually lose employment 
where the rate of increase in productivity is so high and the 
rate of increase in per-capita demand so low that the difference 
between the two is not only negative, but negative to such an 
extent as to make the sum (g+7;-g;) less than zero, or rather 
the sum (g+7;-g;+¢) less than zero, where @ stands for 
the rate of people’s retirement from working activities (6) 
(®) At this point restrictions (V.6), discussed in section 2, may be re- 
written with reference both to the stocks of capital and to employment of 
abour in each single sector. in the following wavy: 
V 
‘continued on following page) 
‘10) Pasinetli - pag. 89