662 PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 28 
comparison, expressions (V.17) only contain technical coef- 
ficients and their rates of change over time; while expression 
(V.18) contains, besides these coefficients and their rates of 
change, also the demand coefficients and their rates of change 
over time. 
There is one immediate conclusion that may be drawn. It 
is not permissible to talk of neutral, capital-saving and labour- 
saving technical progress merely on the basis of changes in 
the over-all capital-output ratio, because technical progress 
is only one of the two factors on which the over-all capital- 
output ratio depends. It would be quite possible, for example, 
to envisage a case in which technical progress is capital-saving 
in each single sector of the economy and nevertheless the 
aggregate capital-output ratio remains constant or even in- 
creases as time goes on, simply because per-capita demand 
is expanding in the direction of highly capital-intensive com- 
modities; and vice versa. This also means that all recent 
discussions on the factors affecting the aggregate capital- 
output ratio, discussions which have stemmed from macro- 
economic models and have focussed only on technology, 
have in fact missed one half of the problem. As emerges from 
the foregoing analysis, any explanation of the movement in 
time of the aggregate capital-output ratio cannot be correct, 
if it does not consider both sides of the problem: the demand 
side as well as the technical side. 
5. A few final remarks may be added about the dynamics 
of the aggregate variables normally used in macro-economic 
Investigations (i.e. national income, total capital, consumption, 
investment, etc.). From the (V. 13)-(V-14) it follows that all 
these aggregate magnitudes move in time in a very composite 
way. Each of them results from a sum of physical quantities, 
whose proportions are changing, multiplied by prices which 
also change as time goes by. Therefore, all of them have a well 
defined meaning at any specific point of time. in relation to the 
10] Pasinetti - pag. 02