322 PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 28

‘hat the relative productivity of two primary inputs depends
only on their distance from each other in time, and this is
exactly what hypothesis (d) says.

3. JUSTIFICATION OF THE MODEL WITH RESPECT TO ITS CON-SEQUENCES


The main points on which conclusions derived from the exponential
 model are justified are the following:

a) Small Inter-country Differences in the Value of the Capital-Output
 Ratio at the Same Point of Time

323. The relation

(323-1)

yo 9
+0 2

shows that if ©, as a technical constant applies to the different
countries considered, the capital-output ratio y should change
but little, for according to the formula such changes cannot be
very great at observed rates of interest and with a value of ©,
of about 4.
Thus, for 1913, I have calculated ®, as (?):

United States
France . .
Great Britain
Average .

3-44
3.83
3.67
2.64

* Relation 251-6.
?) ATLAIS (1060 A), D. 715; (1962 A), PP. 52-53.

11] Allais - pag. 126