We suppose that:
C = 70 + 0.70YD, I = 90, G = 100, T = 0.10Y
(i) Find the equilibrium income.
(ii) What are the tax revenues at equilibrium income? Does the government have a balanced budget?
(i) C=7+0.70 YD
I = 90
G = 100
T = 0.10 Y
Y = C + I + G
=70+0.70YD+90+100
=70+0.70YD+190
=70+0.70(Y−T)+190
=70+0.70Y−0.70×0.10Y+190
=70+0.70Y−0.07Y+190
=70+0.63Y+190
=260+0.63Y
Y−0.63Y=260
0.37Y=260
Y=2600.37
=702.7
(ii) T = 0.10Y
=0.10×702.7
=70.27
Government expenditure = 100
Tax revenue = 70.27
Government has a deficit budget, not a balanced budget because government expenditure exceeds the tax revenue. (G > T)