Suppose that Cascadias economy is described by the following
Solution
(a)
Consumption is as follows -
C = 200 + 0.75YD
Coefficient of YD in above equation represents MPC.
So,
MPC = 0.75
Calculate the government spending multiplier -
Government spending multiplier = 1/(1-MPC) = 1/(1-0.75) = 1/0.25 = 4
The government spending multiplier is 4.
(b)
At equilibrium,
Aggregate spending equals Income
or,
Z = Y
C + I + G = Y [Z = C + I + G]
Y = 200 + 0.75YD + 100 + 200
Y = 200 + 0.75(Y - T) + 100 + 200
Y = 500 + 0.75(Y - 100)
Y = 500 + 0.75Y - 75
0.25Y = 425
Y = 425/0.25 = 1,700
The initial equilibrium level of income is 1,700.
Calculate the increase in income -
Increase in income = Increase in government spending * Government spending multiplier
Increase in income = $25 * 4
Increase in income = $100
The increase in income is $100.
Calculate the new level of income -
New level of income = Initial level of income + Increase in income = $1,700 + $100 = $1,800
The new level of income is $1,800.
(c)
Consumption at the initial level of income -
C = 200 + 0.75YD = 200 + 0.75(Y - T) = 200 + 0.75(1,700 - 100) = 1,400
Consumption at the new level of income -
C = 200 + 0.75YD = 200 + 0.75(Y - T) = 200 + 0.75(1,800 - 100) = 1,475
Increase in consumption = Consumption at the new level of income - Consumption at the initial level of income
Increase in consumption = 1,475 - 1,400 = 75
So,
The increase in consumption is 75.
The new level of consumption is 1,475
(d)
Government spending after increase = $200 + $25 = $225
T = $100
Calculate the budget surplus -
Budget surplus = T - G = 100 - 225 = -125
The Budget Surplus is -125.

