SEMAINE D'ETUDE SUR LE ROLE DE L’ANALYSE ECONOMETRIQUE ETC. 479 
This result shows that when last year’s population increase is 
above average (v,>>v), the savings ratio to be applied in this 
year is below the level that would be applied if the population 
increase would be known to remain constant at the value v. 
This is apparently due to the fact that this year’s population 
‘ncrease is then also expected to be above average, which has 
a negative influence on the savings ratio of this year, see 
(5.1). It is true that the population increases of later years, 
too, are expected to be above average, which has a positive 
influence, but this effect is evidently of less importance. 
The desired rate of increase of per capita consumption, d,, 
need not to be constant. A simple alternative specification is 
(5.09) 
”, 
, @ 
A 
which implies that the desire of the first year is confined to a, 
after which it increases gradually and approaches 4 in the limit. 
The first-period decision of the maximizing strategy under con 
ditions (5.9) and (5.7 iz: 
(5.10) 
1 
On comparing this result with (5.8), we find that the savings 
ratio is equal to that of (5.8) under the assumption that the 
desired increase is constant at the level d, except that a certain 
"71 Theil - pag. 15