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PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 2¢ 
rate was constant and the system was growing at the same rate 
as population; in the case of uniform technical progress just 
examined, population remains constant and the wage rate is 
growing at the same rate as technical progress. The two cases 
may easily be combined, and the results of such a combination 
are so straightforward that it is of no use to spell them out in 
detail here. We may however explicitly state at least the con- 
ditions of equilibrium, which emerge as follows: 
(IV.5) An; nt) = (g + P)ain(t), 
1=1, 2, ..., (n-1), 
and 
(IV.6) 
TS gaan) = 3 om an) alt) = 
= (246) 3 — am (0) auld). 
The economic meaning is evident. Each single sector of the 
system and the system as a whole expand at a rate which is 
the sum of the rate of population growth and of the rate of 
technical progress, a- sum which is widely known in economic 
literature by HARROD’s term of natural rate of growth. This 
natural rate appears explicitly both in (IV.5) and in (IV.6), 
the latter now giving a complete analytical break-down of 
HARROD’s equations. (The aggregate net saving ratio is re- 
quired to be equal to the natural rate of growth multiplied by 
the over-all capital-output ratio) (3). 
At this point, however, after admiring the symmetry and 
the analytical beauty of the two cases of growth considered so 
far, we must also draw from the results we have obtained at 
least two logical and stringent conclusions. 
(3) See the proof in footnote (1) of Chapter IIT. 
[101 Pasinetti - pag. 54