Answer:
A. GDP will increase by $130 billion
B. GDP will increase by $52 billion
Step-by-step explanation:
A. If firms increase their investment by $13 billion and the MPC is 0.9 ,
to get the change in GDP, we multiply the increase in investment expenditure of the firm by the investment expenditure multiplier
ΔGDP = Δ I x 1/(1-b)
Where:
ΔGDP = Change in Gross Domestic Product (GDP)
Δ I = Change in Investment
1/(1-b) = Investment Expenditure Multiplier
b = Marginal Propensity to Consume (MPC)
ΔGDP = Δ I x 1/(1-b)
Δ I = $13 billion
b = 0.9
ΔGDP = $13 billion x 1/(1-0.9)
= $13 billion x 1/(0.1)
= $13 billion x 10
= $130 billion
This means that with marginal propensity to consume of 0.9 and marginal propensity to save of 0.1 i.e. (1-0.9) an autonomous $13 billion change in investment expenditures results in a change in national income of $130 billion change in national income. With MPC of 0.9, the investment expenditure multiplier is 10, that is, any change in investment will have a multiplier effect of 10.
A. If firms increase their investment by $13 billion and the MPC is 0.975
B. ΔGDP = Δ I x 1/(1-b)
Δ I = $13 billion
b = 0.75
ΔGDP = $13 billion x 1/(1-0.75)
= $13 billion x 1/(0.25)
= $13 billion x 4
= $52 billion.
This means that with marginal propensity to consume of 0.75 and marginal propensity to save of 0.25, i.e. (1-0.75) an autonomous $13 billion change in investment expenditures results in a change in national income of $52 billion change in national income. With MPC of 0.75, the investment expenditure multiplier is 4, that is, any change in investment will have a multiplier effect of 4.