SEMAINE D'ÉTUDE SUR LE ROLE DE L’ANALYSE ECONOMETRIQUE ETC 
but recourse to available statistical material to determine 
functions ¢(0) and © (0) directly, and using them to deriv 
and Ô would involve such large estimating errors that the «. .- 
culation of ©, and & from the two preceding relations we 
be completely devoid of significance. 
It is easy to see this. For, from relations (240-5) and 
'240-10) we have 
(314-6) 
y © «302% 
¥ 
so that 
(214-17) 
3 1-0 
®: (i-p) 
or, putting ©, © ÿc as a first approximation 
(314-8) 
5, 
1.-0 
i-p! 
It is obvious that, even where the relative error in © is 
relatively low, the relative error in the difference Yc - © will 
pe high. The same is true of the difference ¢ - ¢ (!). So much 
(") An accurate estimate of i poses obvious difficulties; the same is true 
for n. We have 
> 
An estimate of p in which this parameter is taken as being equal to the 
rate of population growth can clearly only be a first approximation. It 
follows that for small values of i and quite high values of o, the relative 
error in the estimate of i—n can be fairlv large. 
111 Allais - pag. 1710