SEMAINE D'ÉTUDE SUR LE ROLE DE L’ANALYSE ECONOMETRIQUE ETC. 851 
It can thus be seen that the figure of 10% of capital cor- 
responds to 76% of consumed income for inventories, while 
for structural assets the corresponding figures are 61% for 
capital and 119%, for consumed income. For equipment and 
structures as a whole 249%, of consumed income corresponds to 
00% of capital. 
This table has an evident relationship with tables 7, 8 and o. 
The divergence between the amortisation period of some 
17 years, found for equipment and structures considered as a 
whole, compared with values of some 8 and 10 years in tables 8 
and 9 is due to the fact that the assumption has been made in 
the calculations in Table 10 that investment is constituted solely 
of durable goods, and that (given the non-availabilty of valu- 
able data) repair and maintenance outlays included in the 
value of equipment and structures have not been taken into 
account. But the average amortisation period of repair and 
maintenance outlays is probably of the order of two to three 
years, and since their value is relatively high by comparison 
with total investment in new goods, it is probable that in 
a full calculation the g2-~ would be considerably reduced, or 
might even disappear 
) Let C and R be the capital and consumed income corresponding 
to investment, C, and R, the share of that investment represented by new 
goods, and C, and R, the shares represented by repair and maintenance 
autlavs (these svmbols are valid only for the present note). Then 
[f the assumption -- 
Tv 
R.C 
R 
‘hen 
alan 
Thus, if annual repair and maintenance outlays account for 1/4 of the 
total annual resources devoted to investment, the average amortisation 
period falls from 17 to about 13 vears. If it were assumed that repair and 
Âllais - pag. 155