Chapter 3. Problem 2
Consider an economy in which taxes, planned investment, government spending on goods and services, and net exports are autonomous, but consumption and planned investment change as the interest rate changes. You are given the following information concerning autonomous consumption, the magical propensity to consume, planned investment, government purchases and goods and services, and net exports.
Ca =1500-10r c=0.6 T=1800 Ip=2400-50r G=2000 NX=-200
a. Compute the value of the marginal propensity to save.
1-c = s 1 - 0.6= .04 Marginal propensity to save is .04
b. Compute the amount of autonomous planned spending Ap, given that the interest rate equals 3.
Ca – cTa + Ip + G+ NX
1500 – 10(3)- 0.6(1800) + 2400 – 50(3) + 2000 + (-200) =
1500-30-1080+2400-150+2000-200=4440
The amount of autonomous planned spending is 4440
c. Compute the equilibrium level of income, given that the interest rate 3.
Ap/s
4440/.4 = 11100
The equilibrium level of income is 11100
d. Suppose that autonomous consumption changes by 4 percent for any change in household wealth and that the decline in the housing market from 2006-09 and the drop in stock market from 2007-09 reduce household wealth by $3 trillion. Compute the decline in household wealth.
.04(3) = .120 = 120
e. Calculate the new amount of autonomous planned spending Ap, and the new equilibrium level of income, given that the interest rate equals 3.
4440-120 = 4320
4320/.4 = 10800
The new equilibrium level of income is 10800
f. Using your answers to parts c-e, compute the value of the multiplier.
New situation-old situation= change in income
Y/Ap=1/s
Y=(10800-11100)=-300
Ap=(4320-4440)=-120
-300/-120 = 1/.4 2.5=2.5
g. Fiscal and monetary policymakers can spend to the decline in household wealth by taking actions that restore income to its initial equilibrium level. Fiscal policymakers can increase government spending or tax cuts or do both.