SEMAINE D’ETUDE SUR LE ROLE DE L’ANALYSE ECONOMETRIQUE ETC. 
67 
Once we have estimated the future values of these compo- 
nents, which correspond to the forty categories into which we 
divide consumers’ expenditure, we then have the further task 
of converting them into demands for the principal products 
of our thirty-one industries, demands for complementary im- 
ports such as tea, cigars and wine bottled abroad, demands 
for direct labour such as domestic servants, and payments of 
certain indirect taxes. Here we have based our calculations 
largely on our classification converter for 1960. 
Eventually, in view of the increasing importance of consu- 
mers’ durables, for which the process of adaptation is relatively 
slow, we hope to use the adaptive version of the demand model 
described in [7] [35]7. 
2) Public consumption. Here we have made use of the 
trends suggested in the report of the National Economic De- 
velopment Council [50]. Eventually we hope to get a new 
view on some of the components of public consumption 
through the addition of new circuits to the model, such as the 
circuit relating to education and training. 
3) Public expenditure on social capital. These estimates 
are rough and subjective. For example, investment in educa- 
tional buildings is assumed to rise in proportion to current 
expenditure on education; the road-building programme is as- 
sumed to treble between 1960 and 1970. Gross investment in 
dwellings is similarly estimated at the present stage. 
4) Exports. Here we have again based ourselves on the 
work of the National Economic Development Council [50] 
but have scaled down their annual growth rates for 1061-1066 
in making our estimates for 1060-1940. 
5) Industrial replacements. These are based on a study 
of investment statistics and of the life-spans of different types 
1] Stone - pag. 65