where
«1 = 1/(1 - c(Y))
(6)
c(Y) - the marginal propensity to consume is a function of the real per
capita income
Other variables could be included to explain the investment multiplier, e.g. the
marginal (inland) propensity to invest, the marginal propensity to import etc.
Therefore c is here an “aggregate” marginal propensity to consume. The functional
form for estimation of the investment multiplier was, after relative and absolute
income
«1 = αio - anDY
«1 = βo - β1Y1
(7)
(7a)
where the expected sign of β1 is negative while β0 is positive.
The point of departure for discussing β now becomes
GI = γo + Y1 DY
GY = αo + a1GI
«1 = «10 - O11dy
(8)
(9)
(10)
Now the distribution of growth on regions is described by a second degree polynomial
DGY = ( (X1oY1 - (X11Yo )DY - (X11Y1DY2
(11)
The coefficient γ1 is here crucial because it indicates to which degree the investment
growth is unequally distributed in relation to the income distribution
Equal growth as a function of γ1 is found by solving
(ɑɪoɪɪ - ɑɪɪɪo )DY - «11Y1DY2 = 0
(12)
The condition for an equal regional growth at an unequal distributed DFI is for a
given “aggregate” consumption function is now given by
Y1 = «11Yo/( «1o - «11DY)
(13)