SEMAINE D'ÉTUDE SUR LE ROLE DE L’ANALYSE ECONOMETRIQUE ETC. 20

4
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DUAL MODEL OF ECONOMIC GROWT.x

[. A NEW DEVELOPMENT

[ shall now exemplify the ideas on model-building expressed
 in the first section of the preceding chapter in terms of the
model of the British economy on which I and my colleagues
are working. Four progress reports on this work have already
appeared in this series [7] [8] [9] [10]. In the first of these
we began by setting up a single model for a future state of
steady growth and, in our conclusions, hinted at the need for
an extension of the model which would help us to plot out a
path from the present to the future state. This extension is
now beginning to take shape.
In this short chapter, I shall outline the two parts of the
model and explain how they interact. In chapter IV, I shall
review in greater detail the structure of the first part, our original
 model, and discuss a number of modifications we are bringing
 to it. Finally, in chapter V, I shall describe the structure of
‘he second part, on which we have recently started work.
[n my exposition I shall try to bring out: the organic chacacter
 of the model, that is, how its structure and relationships
tend to change as knowledge is accumulated; the receptiveness
of the model to observations from different sources, including
sstimates from industrial experts and others, which can improve
 its realism; and the degree of consistency which we trv to
impose on the model F--"

1] Stone - pag. 2,