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PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 
exactly the same procedure as in section 2 of the previous 
chapter, the capital accumulation conditions emerse as 
(IV.3) a, »(t)=pa,, (1), 1=1, 2, .... (n-1), 
which are similar to the (III.6), the only difference being that 
now the rate of technical progress has replaced the rate of 
population growth. Of course in the (IV.3) all coefficients are 
moving, but they are moving at the same rate of change so 
that the relation between them remains constant through time. 
The effective demand condition also emerges as very similar 
to (111.11): 
(V4) 1-3 Senda = (e+) 3 5 anid and, 
where again the rate of technical progress has taken the place 
of the rate of population growth. The interesting property of 
this case is that all coefficients of production and all coef- 
ficients of consumption, although moving in time, are moving 
in an opposite direction and at exactly the same rate. As a. 
result, each single binary product of coefficients under the 
two summations remains constant as time goes on — the mo- 
vements of the components exactly cancelling each other out. 
This means that the contribution to national income of each 
single sector remains constant. As in the previous case, con- 
dition (IV.4) does not raise any problem through time. Once 
it is satisfied at time zero, it will remain satisfied for ever, 
pecause in all sectors productivity and demand are increasing 
at the same rate. 
The time paths of all economic magnitudes can be found 
immediately by substituting (IV.1) and (IV.2) into (II.11), 
(IT.14) and (III.12)-(I1I.15). As can easily be checked, if the 
rate of profit remains constant, the results emerge as follows: 
r) physical production of each commodity increases in time 
at the rate p; 
‘10] Pasinett: - pag. 52