SEMAINE D'ETUDE SUR LE ROLE DE L’ANALYSE ECONOMETRIQUE ETC. 
y. 
~ _NERAL COMMENTS 
Constancy of ® 
330. The observed stability over both time and space of the 
coefficient ®, may at first sight seem extraordinary. However, 
on further reflection, and in the framework of the model, this 
stability becomes much less astonishing. It expresses the fact 
‘hat whatever the state of knowledge, the decrease in the pro- 
ductivity of the factors of production as they become more 
distant in time remains constant. In a certain sense, this is 
an index of the conceptual difficulty involved in thinking about 
roundabout brocesses (1. 
Estimation of © and the Distribution of the Active Population 
331. There is a manifest relation between the value of the 
average amortization period ® and the composition of the work- 
‘ng population, and it would seem reasonable to envisage esti- 
mating the value of ® directly in order to compare it with its 
theoretical value, which in the case of the exponential model ic 
(~~ —N 
Ou I-2 7 
") Relation 
‘?) Relation 
(211-0) and 
251-11) 
y 
Allais - pag. 15.