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

v4.3

assumed as an exogenous datum is the set of consumers’ preferences.
 Thus, as time goes on, the shape of these consumers’
preferences and the movements of technical coefficients postulated
 by (V.2' determine the time movements of the ve
may write

V.3)

cdg eee @

a
dt [an ..

a.

a, IB:

a

Ah

c

where the fs depend on the shape of the consumers’ preferences,
 which are defined in such a way as to satisfy propositions
a), b), and c) of chapter IV section 6, graphically represented
in fig. 1. The technical coefficients that appear in (V.3) induence
 the 7;’s through the medium of two channels: the level
and the rate of change of real per-capita incomes, and the
variation of the structure of prices.
Here, for purposes of simplicity and symmetry, the assumption
 will be made that the movements of per-capita demand
may approximately be broken down (if we represent them on
a logarithmic diagram) into stretches of straight lines. In other
words, we assume that time can be divided into finite stretches
of length s (larger than the unit of time we are adopting)
within which, for each commodity i, the percentage rate of
change of demand 7, remains constant. Then passing from
one stretch of time of length s to the next, r; changes, remainng
 then constant again for another stretch of time s And
30 on.
Therefore, bv defining now a new variable v as

101 Pasinetti - pag. 73