General Business 765                                        Student Name ______________________

Spring 2002                                                     ID Number ________________________

Answers to Homework #4

 

1.  (8 points )  Suppose you are using the Keynesian Model to model an economy.  Suppose the MPS with respect to disposable income is .2 and that taxes are given by the equation T = 5 + .25Y (i.e., taxes are now a function of income and will vary as the level of income in the economy varies).

a.  Since T = 5 + .25Y, this implies that the tax expenditure multiplier equals

 (-b/(1 – b +bt))

where b = MPC and t = the marginal tax rate.  The value of this expression equals (-2) numerically, so for a $500 increase in aggregate income taxes must be decreased by $250.

b.  –2

c.  The government expenditure multiplier equals 2.5.  Thus, for a $500 increase in aggregate output, government spending must increase by $200.

d.  2.5

 

2. (14 points)  Suppose you are told that when disposable income is $100, consumption is $80 and when disposable income is $250, consumption is $200.  Furthermore, suppose that taxes are autonomous and equal to $10.

a.  MPC = .8

b.  a = 0

c.  a’ with respect to aggregate income = -8

d.  equilibrium aggregate output = 260

e.  Leakages = Injections in equilibrium.  When Y = 260, then S = 50 and the equation S + T + M = I + G + X.

f.  Since the equilibrium level of output, Y, equals 260 then 52 people are employed.

g.  If employment increases by 50% then you want total employment to be 78 people.  This level of employment implies a level of output equal to $390. To get an increase of $130 in aggregate output would require a change in government spending of $26.  Total government spending would therefore equal $46.

 

3.  (20 points)  Suppose you are told that the MPS is equal to .2 for this economy and that taxes, investment spending, government spending, and net export spending are all autonomously determined in this economy.

Y

T

Y – T

C

S

I

G

X – M

AE

Direction of change in Y

1000

100

900

820

80

100

100

200

1220

increase

2000

100

1900

1620

280

100

100

200

2020

increase

3000

100

2900

2420

480

100

100

200

2820

decrease

4000

100

3900

3220

680

100

100

200

3620

decrease

6000

100

5900

4820

1080

100

100

200

5220

decrease

a.  Fill in the above table.

b.  C = 20 + .8Y

c.  equilibrium level of output Y = $2100

d.  employment = 210

e.  Labor productivity = $10/person

f.  5

g.  the change in Y = 500, so the new equilibrium level of output equals $2600

h.  the new level of employment equals 350, so the change in the level of employment is 115  people

i.  Labor productivity = $8/person

j.  Two graphs:  one of the Keynesian cross with two different AE functions, and the other of a aggregate production function showing an increase in the level of employment.

 

4.  Answer the following question using the data for a financial system given in the table below (data are in millions of dollars).

 

Bank Reserves                                                            10

Demand Deposits                                                100

Cash in the Hands of the Public                                    100

Savings-type accounts                                                200

Large Denomination Time Deposits                        100

Small Denomination Time Deposits                        50

Noninstitutional MMMF Balances                        400

Other Checkable Deposits                                    150

Travelers Checks                                                10

 

a.  M1 = $360 million

b.  M2 = $1010 million

c.  4% or .04

d.  the change in demand deposits is equal to the money multiplier times the change in reserves, or (25)(10 million) = $250 million