SEMAINE D'ÉTUDE SUR LE ROLE DE L ANALYSE ECONOMETRIOUE ETC 
99G 
For France, Great Britain and the United States in 1913 we 
find an average value of y of 3.64. For the U.S.A. from 1880 to 
1956, we find 3.46 and the median of 58 values given for 21 coun- 
tries by CoLIN CLARK is 3.54 (§ 323-1). Such agreement cannot 
be due to chance. 
Ordinarily if we have a theory and the facts are in disagreement 
with this theory, the theory is rejected. But here the objection is 
quite different. It is that if there is agreement we cannot infer 
anything because the data are questionable. Perhaps we ought to 
reject the facts because they are in striking agreement with the 
model? 
The second objection was rather more justified. Professor FISHER 
noticed that the range of variation of ©, was a little greater than 
the rate of variation of y. And, in the light of this theory. we 
should have smaller variations for @®. because we have 
325-1, 
©, being a constant and y a function of :. 
In fact, I have given the relative deviation of y and ©, from 
their averages for the United States in my Econometrica “er 
(1962). I found 5% and 8%; the difference is not so grc=* Jor 
United States, Great Britain and France in 1913 we hav, and 
3%. Here it is true that the first figure is greater than the second. 
But in any case the extent of the range of ®_ can be ec" plained 
by the difficulty of estimating the rate of interest correctl Tn fac 
we have 
| Allais - pag. 303