SEMAINE D'ÉTUDE SUR LE ROLE DE L’ANALYSE ECONOMETRIQUE ETC.
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are described independently of time, once and for all time.
As a result, these models do not say about the structure of
an economic system anything more than what is already said
hy the corresponding static model. They add to it a projection
through time, by taking the structure of the system at a given
point of time and crystallising it — so to speak — for all
sternity. The picture which emerges is that of a hypothetical
economic system growing only in size but with no develop-
ment. Each member of the community goes on indefinitely
oroducing the same commodities, quantitatively and quali-
tatively, receiving the same per-capita income and consum-
ing the same consumption goods. We have already discussed
this type of system, and acknowledged its logical consistency
and beauty, as a mathematical exercise, in chapter III, at the
same time pointing out, with reference to any progressive eco-
nomic system, its lack of practical relevance.
I should not, therefore, come back to the subject if
it were not for the fact that once concepts are coined, they
tend to be generally used. And although neither von NEU-
MANN nor LEONTIEF ever extended their conclusions outside
the fixed framework they adopted, the economists who are
now-a-days using these concepts do not always appear to be
so strict. It is indeed not infrequent, among economists, espe-
cially to talk of von NEUMANN’s maximum uniform rate of
growth as if it were a concept of general validity; and in
particular as if it were applicable to a growing economic
system in which there is technical progress. Since exten-
sions of this type are unjustified, and since they distort
che very purposes of VoN NEUMANN’s theoretical scheme, it
may be useful to show explicitely why thev must be firmly
resisted.
Suppose the simplest type of technical progress, from an
analytical standpoint; i.e. suppose that improvements take
he form of increases in productivity uniformly spread over
all sectors. In this case, it is only too natural to abandon
to] Pasinetti - pag. 111
