676 PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 28 
tables can be compared (comparative statics analysis), but 
they cannot be analytically linked to one another — no theory 
of any generality can be provided for passing from the one 
to the other (*). The continuity in time is kept, on the other 
aand, at the vertically integrated level, where the relations 
which can be set up possess — to use FriscH-HAAVELMO’s 
terminology (°) — a higher degree of autonomy. This means 
that the permanence of these relations in time is independent 
of technical change. In this context, the vertically integrated 
technical coefficients acquire a meaning of their own, inde- 
pendent of the origin of the single parts which compose them. 
The movements of these coefficients through time, and the 
various consequences thereof, can be investigated and follow- 
ed as such. When more information is needed about the 
() A note may be added here about how this applies to the work which 
is being done at present at the Department of Applied Economics of Cam- 
bridge, where Professor Stone, Mr. BrowN and their colleagues are working 
on a model of economic growth for the U.K. from 1960 to 1970. They seem 
to be trying to make an estimate of the 1970 input-output table by applying 
uniform coefficients of reduction to the rows of the table for 1960. (See: 
RICHARD STONE and ALAN BROWN, 4 Computable Model of Economic Growth, 
D.A.E. Cambridge 1962, especially pp. 70-71). 
The procedure, as such, hardly has any theoretical justification if 
technical progress follows the pattern which has been described in the text. 
Yet, since the period considered is not too long and since the table adopted 
is rather aggregate (of the order of 30 industries), which means that the 
industries considered are not very far from being vertically integrated sectors, 
the results obtained thereby may turn out to be not too unsatisfactory 
after all, 
One should realize, however, that whatever degree of satisfaction there 
may be in the results, it cannot be attributed the procedure, which is 
unacceptable in principle. It is to be attributed to (and will be greater, 
the greater the degree of) shortness of the period considered, and aggregation. 
i.e. vertical integration, of the industries considered. 
(°) TryGgve HaaveLmo, The Probability Approach in Econometrics, Suppl. 
to « Econometrica », July 1944. The process of passing from inter-industry 
to vertically integrated relations for the purpose of dynamic analysis seems 
to be a typical example of what HAAVELMO describes as a way of passing 
to more fundamental and autonomous relations. « In scientific research, 
our search for explanations consists of digging down to more fundamental 
relations than those that appear before us when we merely stand and look. 
Each of these fundamental relations we conceive of as invariant with respect 
to a much wider class of variations than those particular ones that are dis- 
played before us in the natural course of events » (ibid.. p. 28) 
"107 Pasinetti - pag. 106