364 PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 28

(H), (H'), (H”) and (H””) cannot be considered as rigourously
valid, and the computations have involved a certain number
of further approximations. At the same time, the non rigorous
 validity of hypotheses (H) to (H'”) may account for the
divergences noted between the various estimates that have been
derived.
Be this as it may, the rather striking coherence in the whole
set of results derived using these different assumptions and
applying quite rough calculating techniques, does seem to
show, given the apparently reasonable nature of the interpre-‘ahons
 (H), (H”), (H”) and (H””) which have been succesively
considered, that the exponential hypothesis can be considered
as a fairly close reflection of reality.

12) Finally, the results of the analysis described above
are not out of line with data based on the composition of the
labor force.

a) Given the composition of the labor force, the estimate
derived from the above analysis that the share of primary
‘ncome devoted to investment is of the order of 30% to 35%
seems quite reasonable. Thus, in 1955, the composition by
sector of the working population in the U.S.A. was (1):

Agriculture
[ndustry .
Mining .
Construction .
Transport .
Trade . .
Services . .
(Government

Total

(*) Statistical Abstract, 1959, pp. 206 and 2ro.
of these figures is beyond the scope of this paper

11.8%
29.2%
1.4%
4-9%
7.2%
23.0%
10.4%
12.19%,

[OO

"J.
/

A detailed discussion

11] Allais - pag. 168