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Ch. 2 : National Income Determination (I). (Simple Keynesian Model). The national output or income of an economy is at equilibrium when Aggregate Demand (AD) = Aggregate Supply (AS) [which is the amount of national output (Y) produced in the economy. ]. At equilibrium, Y=AE.
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Ch. 2 : National Income Determination (I) (Simple Keynesian Model)
The national output or income of an economy is at equilibrium when Aggregate Demand (AD) = Aggregate Supply (AS) [which is the amount of national output (Y) produced in the economy. ]
At equilibrium, Y=AE
Y = output = income
AE = aggregate expenditure AE = C + I (planned consumption expenditure + planned investment expenditure)
Consumption Function • C = Ca + cY • Ca = autonomous consumption • cY = induced consumption • c = marginal propensity to consume
C C=Ca + cY slope = 0.75 20 Y
Example • C = 20 + 0.75Y
C C=Ca + cY slope = c Ca Y
Investment Function • I = Ia • the investment function is assumed to be autonomous
Example • I = 20
I I=Ia Y
I I=20 20 Y
Equilibrium Condition Y = AE = C + I
AE 450 Y
AE AE=C+I Y Y*
AE AE=C+I+G+(X-M) Y Y*
$ S+T+M I+G+X Y Y*