134 PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 28

The value of reproducible capital is several times that of
national income. Errors arising from the conventional estimaling
 procedure may not be very considerable relative to capital
 (1), but they will be significant in relation to the evaluation
of depreciation and of G.N.P.
The value of the grocer’s boy’s or of the waiter’s services
should be counted as a production of capital; it is an element
of gross investment and therefore of Gross National Product P.

Demonstration of the Equality A =R,

It is a simple matter, using the preceding formulation, to
show the passage from A’ to A. Conventional accounting only
considers as capital those goods whose longevity exceeds a
certain duration. Thus with the notation of Table 2 (§ 111)
the corresponding concept of the general model which is presented
 in this paper is

(116-14) A* = [ FR (2,6) db

r J
Le

If the usual convention is modified and 6, made to tend to
zero, then for A. =0 relation (111-1) gives

(116-15) CC A=A*[9,=0]=R, .

(') See below § 334, Table 8 and o.
(*) In fact, under the usual concept the investment in a tool is considered
 as made when this tool is put in service. With such a concept
depreciation A’ includes interest.
Nevertheless from an economic point of view, this is only an intermediate
 stage and the original investment takes place when the primary
output (as defined in § 111) are supolied.

[11] Allaic - pag. 38