SEMAINE D ETUDE SUR LE ROLE DE L ANALYSE ECONOMETRIQUE ETC 
DDL 
amortisation period for 
In other words, if we take the 
condition 
(420-2) 
Thus Rey is maximised for 0: € 
This means that of all growth processes, the most advan 
tageous 1s that for which the rate of increase of primary incomes 
IS zero. 
This apparently paradoxical result is easily explained when 
it is remembered that if population is increasing (and even sup- 
posing that natural resources increase at the same rate, which 
they don’t), this growth implies that every year some propor- 
tion of gross national product must be allocated to maintain the 
volume per capita of equipment and durable consumption goods 
at the same level. 
From the preceding relation, this diminution of consumable 
production is equal in relative terms to 
(420-3 
ct 
and we have for small values ot y 
420-4, 
r'6, 
It further follows from relation (420-1) that a negative rate 
of growth (population decline) would be advantageous. This 
finding is valid so long as the assumptions, the consequence of 
which is the constancy of (i ¢), remain valid. But these ass- 
{1:] Allais - pag. 189