SEMAINE D'ÉTUDE SUR LE ROLE DE L ANALYSE ECONOMETRIOUE ETC. 
621 
2. A dynamic model with uniform technical progress and uni 
form expansion of demand 
After dealing with the case of population increase and cons- 
tant returns to scale, the hypothetical case of economic growth 
taking place with uniform technical progress and uniform ex- 
pansion of demand can be treated more summarily. 
The assumptions are now as follows: 
a) the initial conditions, as in the previous case, are such that 
at time zero there is full employment and full capacity 
utilization: 
D) as time goes on, population remains constant; 
c) there is the same technical progress in all sectors of the 
economy. This means that, as time goes on, all the technical 
coefficients of production decrease at a steady percentage 
rate ¢, i.e. 
IV.1) a, (t)=a,, 
— 1, Lis ……0… (n- 1), k,, R-, “ee rR, 
d) consumers’ tastes are such that the composition of con- 
sumption is invariant to changes in income. In other words, 
when income increases, each individual expands demand of 
all the commodities consumed in the same proportion. This 
means that, if per-capita income increases at a percentage 
rate p through time (as in equilibrium it must do), all coef- 
ficients of consumption will also increase at the rate p, i.e. 
IV. 2) 
a. (t) = a; U } et 
Ly 25 eens (n - Ir 
Under these assumptions, the two conditions for a dynamic 
2quilibrium come out rather straightforwardly. By following 
10] Pasinetti - pag. 51