FILE: 252N06.HTML

FALL 2005

CLASS NOTES FOR ECONOMICS 252/WEEK 6

DR. WILLIAM SHINGLETON

PLEASE NOTE: THE USE OF CALCULATORS IS ALLOWED ON DR. SHINGLETON’S QUIZZES AND EXAMS BUT THEY CANNOT BE SHARED BETWEEN STUDENTS.

ADD DATA REPORT/TALK ABOUT NEWS

RETURN/REVIEW QUIZ

 

LAST WEEK CH 9

IMPORTANT CONCLUSIONS

          ECONOMISTS AGREE SHORT-RUN FAILURE IS POSSIBLE

                    EQUILIBRIUM CAN BE ANY NUMBER OF JOBS

 

          INCREASED AD DOES NOT SHIFT AS

          INCREASED AS DOES NOT SHIFT AD

 

          UNLESS EXPECTATIONS ARE INVOLVED

 

          AD/AS EXPLANATION OF RECESSIONS

                   TEXT USES AD EXPLANATION

                   EXPLAIN INCONSISTENCY WITH DATA

 

 

CONSUMER SPENDING/CONSUMPTION FUNCTION

          C = DPI - SAVING

          MARGINAL PROPENSITY TO CONSUME  (MPC)

          CONSUMER CONFIDENCE

 

 

SALES =  PRODUCTION

          SALES =  C + I + G + X - M

          AT WHAT GDP DOES PRODUCTION = SALES?

          EQUILIBRIUM  GDP = SALES =  C + I + G + X – M

          TEXT USES DPI = FRACTION OF TOTAL

 

 

 

THIS WEEK

MULTIPLIER PROCESS CH 10

 

 

4 JUNK CONCEPTS (DON’T BOTHER WITH THIS IDIOTIC STUFF)

          45 DEGREE LINE

          INFLATIONARY GAP

          RECESSIONARY GAP

          DEMAND PULL INFLATION

 

 

MULTIPLIER EFFECT/ADJUSTMENT CYCLE

          dSALES => dGDP => dDPI => dSALES

 

          d CONSUMER SALES = MPC * dDPI

          LEAKAGES (SAVING, TAXES, IMPORTS)

          INJECTIONS (INVESTMENT, GOVERNMENT, EXPORTS)

          INVENTORIES AS THE SYMPTOM

 

 

DO FLEXIBLE INTEREST RATES BALANCE SAVING AND INVESTMENT?

          YES: CLASSICAL ECONOMISTS

                             SUPPLY AND DEMAND

 

          SOMETIMES: KEYNESIAN SCHOOL

                             CREDIT CONDITIONS

                                       DECLINING SALES-> LESS INVESTMENT

 

                             BUSINESS CONFIDENCE

                                       DECLINING SALES-> LESS INVESTMENT

 

                             ACCELERATOR HYPOTHESIS

                                       DECLINING SALES-> LESS INVESTMENT

                                       IDEAL OUTPUT = .75 * CAPACITY

 

                             BUSINESS TAXES

                                      NO INVESTMENT WITHOUT PROFIT

 

MULTIPLIER PROCESS: THE LOGIC

 

          dSALES => dGDP => dDPI => dSALES

 

          FINAL CHANGE IS A MULTIPLE OF ORIGINAL CHANGE

 

 

MULTIPLIER PROCESS: THE MECHANICS:

 

          MULTIPLIER = 1/(1-MPC)

 

          SHOW AND EXPLAIN/USE WORKSHEET DATA

 

 

WORKSHEET DATA

 

PROBLEM SET NUMBER 1.1

 

CONSUMPTION     C =  200+.60*DPI

INVESTMENT      I =  400

GOVERNMENT      G =  600

TRADE BALANCE   X = -200

TAXES           T =    0

ANSWERS

GDP                   2500

DISPOSABLE INCOME     2500

CONSUMER SPENDING     1700

SAVING                 800

 

PARTIAL SOLUTION TO FIRST EXAMPLE

 

EQUILIBRIUM => GDP = C + I + G + X

               GDP = 200 +.60 * DPI + 400 + 600 + -200

               GDP = 1000 +.60 * DPI              

                    NOTE THAT DPI = GDP - TAX

                              DPI = GDP - 0

                              DPI = GDP

               GDP = 1000 +.60 * GDP

               .40 * GDP = 1000              

               GDP = 1000/.40

               GDP = 2500

 

 

 

 

 

 

PROBLEM SET NUMBER 1.2 AND 1.3

 C = 400+.75*DPI           C = 2500+.80*DPI

 I =  800                  I =  700

 G = 1200                  G = 1400

 X = -400                  X = 1000

 T =    0                  T = .10

 

ANSWERS

GDP    8000                    20000

DPI    8000                    18000

CONSUMER SPENDING

       6400                    16900

SAVING 1600                     1100

 

 

 

MULTIPLIER EFFECT

MULTIPLIER CONCEPT

dSALES => dGDP => dDPI => dSALES

BE ABLE TO EXPLAIN THE SEQUENCE OF EVENTS

 

 

 

 

 

 

 

 

 

PROBLEM SET NUMBER 2.1

 

CONSUMPTION   C=400+.75*DPI

INVESTMENT    I =  450

GOVERNMENT    G =  200

TRADE BALANCE X =  500

TAXES         T =    0

 

ANSWERS     GDP = 6200

CONSUMER SPENDING   5050

SAVING            1150

 

PROBLEM SET NUMBER 2.2

 

C=   400+ .75*DPI

I =  400

G =  200

X =  600

T =  .20

ANSWERS

GDP                   4000

DISPOSABLE INCOME     3200

CONSUMER SPENDING     2600

SAVING                 600

 

 

 

 

 

PROBLEM SET NUMBER 2.3

C = 8000 +.80*DPI

I = 24,000

G = 4600

X = -600

T = .20

 

 

 

 

DISCUSSION QUESTIONS

 

1. FIND THE EQUILIBRIUM LEVEL OF OUTPUT.

 

2. AT EQUILIBRIUM, HOW MUCH DO CONSUMERS SPEND?

HOW MUCH DO THEY SAVE?

 

3. WHAT IS TAX REVENUE?  WHAT IS THE FEDERAL DEFICIT?

 

4. IN THE LAST PROBLEM, IF A DECREASE IN BUSINESS CONFIDENCE WOULD CAUSE INVESTMENT SPENDING TO FALL TO 15,000, WHAT WOULD BE THE ANSWERS FOR THE ABOVE QUESTIONS?

 

5. IN EACH PROBLEM, IF INVESTMENT SPENDING ROSE BY TWO PERCENT, WHAT WOULD BE THE ANSWERS FOR THE ABOVE QUESTIONS? HOW DO THE ANSWERS TO (4) COMPARE TO THE ANSWERS IN (5)?

 

6. IN EACH PROBLEM, IF THE CONSTANT IN THE CONSUMPTION

FUNCTION ROSE BY 1000, WHAT WOULD BE THE ANSWERS FOR THE  ABOVE QUESTIONS?  HOW DO THE ANSWERS TO (6) COMPARE TO THE ANSWERS IN (5)?

 

7. SUPPOSE THAT OUTPUT WAS 400 ABOVE (OR BELOW) EQUILIBRIUM.  HOW AND WHY WOULD THE PRIVATE SECTOR RESPOND?  WHAT WOULD BE THE BEGINNING AND FINAL TOTALS FOR SALES?  EXPLAIN THE ADJUSTMENT PROCESS. FOCUS ON THE INVENTORY SIGNAL.

 

8. MOST GDP NUMBERS ARE HEADLINED IN THE NEWSPAPERS AS

PERCENTAGE CHANGES.  WHAT COULD CAUSE A 5 PERCENT INCREASE IN GDP IN EACH OF THE ABOVE CASES?

 

9. WHAT CAN YOU SAY ABOUT THE UNEMPLOYMENT RATE IN EACH CASE?

 

 

 

 

 

PROBLEM SET NUMBER 3

 

CASE 3.1

 

C =   6000 + .75 DPI

I =  13000

G =  10350

X =  -7250

TAX =  .10

ANSWER

GDP =  68,000

 

CASE 3.2

C=    7000 + .70 DPI

I =   6000

G =   3800

X =   8000

TAX =  .20

ANSWER

GDP =  20,000

 

CASE 3.3

C=   32000 + .80 DPI

I =   1600

G =   6400

X =    160

TAX = .15

ANSWER

GDP =  124,500

 

 

 

 

 

 

 

FOR EACH CASE:

 

1. FIND THE EQUILIBRIUM OUTPUT.

 

2. AT EQUILIBRIUM, HOW MUCH DO CONSUMERS SPEND?  WHAT IS TAX REVENUE?  WHAT IS THE FEDERAL DEFICIT?

 

3. IF INVESTMENT SPENDING ROSE BY 10% WHAT WOULD BE THE NEW ANSWERS FOR THE ABOVE QUESTIONS?

 

4. SUPPOSE OUTPUT WERE $1000 (A) BELOW OR (B) ABOVE

EQUILIBRIUM.  HOW AND WHY WOULD THE PRIVATE SECTOR RESPOND? WHAT WOULD BE THE INITIAL AND FINAL VALUES OF C, T. AND I?

 

5. SUPPOSE THAT THE GOVERNMENT WANTED TO (A) INCREASE OR (B)  REDUCE INCOME BY $1000.  HOW COULD THIS BE DONE?  GIVE AT LEAST THREE OPTIONS, INCLUDE THE SPECIFIC NUMBERS.

 

6. HOW WOULD A CHANGE IN THE MARGINAL TAX RATE AFFECT THE SYSTEM?

 

7. MOST GDP NUMBERS ARE HEADLINED IN THE NEWSPAPERS AS

PERCENTAGE CHANGES.  WHAT COULD CAUSE A 5 PERCENT INCREASE IN GDP IN EACH OF THE ABOVE CASES?

 

8.  THERE ARE NO INTEREST RATES IN THE ABOVE MODELS.  HOW WOULD INCLUDING A ROLE FOR INTEREST RATES AFFECT YOUR ANSWERS? WOULD THE CHANGES BE LARGER OR SMALLER?  WHY?

NEXT WEEK:

FISCAL POLICY FOR POLLYANNA                 CH 11