334 
PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 28 
6) The estimates of capital-output ratios y and Yc given 
in § 320 and § 326 have been calculated on the basis of avail- 
able figures for national income. In point of fact, the compi- 
ation of these figures is subject to many conceptual difficulties, 
and the data must be adjusted if they are to be used for even 
a midly rigorous application of formulations in the present 
study. It may be helpful at this point, to illustrate the problem 
by examining data for the U.S.A. economy in 1956. 
(n that year, it is possible to take as a first approximation: 
i =2.55% 
i 
7} 
? 
:=4.7% 
=0.85% 
() à here is the pure rate of interest in wage units, since the unit of 
valuation in the present study is the unit of primary income i.e, the basic 
hourly wage rate ($ 110). In my New York lecture, published in « Econo- 
metrica » in 1067. I calculated 
- m 
os 
Z 
where i, is the pure rate of interest in nominal terms and ¢ the rate of 
growth of hourly wage rate (p. 714). 
() § 326. 
() Since the composition of reproducible capital is fairlv stable over 
ime. as a first approximation, it is possible to take 
al 
— A 
dt 
L 
11] Allais - pag. 138