Macroeconomics宏经计算题.ppt

1、A C T I V E L E A R N I N G 2: Computing GDP,1,Use the above data to solve these problems: A. Compute nominal GDP in 2004. B. Compute real GDP in 2005. C. Compute the GDP deflator in 2006.,A C T I V E L E A R N I N G 2: Answers,2,A.Compute nominal GDP in 2004. $30 x 900 + $100 x 192 = $46,200 B.Comp

2、ute real GDP in 2005. $30 x 1000 + $100 x 200 = $50,000,A C T I V E L E A R N I N G 2: Answers,3,C.Compute the GDP deflator in 2006. Nom GDP = $36 x 1050 + $100 x 205 = $58,300 Real GDP = $30 x 1050 + $100 x 205 = $52,000 GDP deflator = 100 x (Nom GDP)/(Real GDP) = 100 x ($58,300)/($52,000) = 112.1,

3、A C T I V E L E A R N I N G 1: Calculate the CPI,4,CPI basket: 10 lbs beef, 20 lbs chicken The CPI basket cost $120 in 2004, the base year.,A.Compute the CPI in 2005. B.What was the CPI inflation rate from 2005-2006?,0,A C T I V E L E A R N I N G 1: Answers,5,0,A.Compute the CPI in 2005:,Cost of CPI

4、 basket in 2005= ($5 x 10) + ($5 x 20) = $150 CPI in 2005 = 100 x ($150/$120) = 125,CPI basket: 10 lbs beef, 20 lbs chicken The CPI basket cost $120 in 2004, the base year.,A C T I V E L E A R N I N G 1: Answers,6,0,CPI basket: 10 lbs beef, 20 lbs chicken The CPI basket cost $120 in 2004, the base y

5、ear.,B.What was the inflation rate from 2005-2006?,Cost of CPI basket in 2006= ($9 x 10) + ($6 x 20) = $210 CPI in 2006 = 100 x ($210/$120) = 175 CPI inflation rate = (175 125)/125 = 40%,A C T I V E L E A R N I N G 2: Substitution bias,7,CPI basket: 10 lbs beef, 20 lbs chik 2004-5: Households bought

6、 CPI basket. 2006: Households bought 5 lbs beef, 25 lbs chik.,A.Compute cost of the 2006 household basket. B.Compute % increase in cost of household basket over 2005-6, compare to CPI inflation rate.,0,A C T I V E L E A R N I N G 2: Answers,8,CPI basket: 10 lbs beef, 20 lbs chik Household basket in

7、2006: 5 lbs beef, 25 lbs chik,0,A.Compute cost of the 2006 household basket. ($9 x 5) + ($6 x 25) = $195,A C T I V E L E A R N I N G 2: Answers,9,CPI basket: 10 lbs beef, 20 lbs chik Household basket in 2006: 5 lbs beef, 25 lbs chik,B.Compute % increase in cost of household basket over 2005-6, compa

8、re to CPI inflation rate. Rate of increase: ($195 $150)/$150 = 30% CPI inflation rate from previous problem = 40%,0,A C T I V E L E A R N I N G 4: Exercise,1980: CPI = 90, avg starting salary for econ majors = $24,000 Today: CPI = 180, avg starting salary for econ majors = $50,000 Are econ majors be

9、tter off today or in 1980?,10,0,A C T I V E L E A R N I N G 4: Answers,11,Solution Convert 1980 salary into “todays dollars” $24,000 x (180/90) = $48,000. After adjusting for inflation, salary is higher today than in 1980.,1980: CPI = 90, avg starting salary for econ majors = $24,000 Today: CPI = 18

10、0, avg starting salary for econ majors = $50,000,0,A C T I V E L E A R N I N G 1: Exercise,Suppose GDP equals $10 trillion, consumption equals $6.5 trillion, the government spends $2 trillion and has a budget deficit of $300 billion. Find public saving, taxes, private saving, national saving, and in

11、vestment.,12,A C T I V E L E A R N I N G 1: Answers,Given: Y = 10.0, C = 6.5, G = 2.0, G T = 0.3 Public saving = T G = 0.3 Taxes: T = G 0.3 = 1.7 Private saving = Y T C = 10 1.7 6.5 = 1.8 National saving = Y C G = 10 6.5 2 = 1.5 Investment = national saving = 1.5,13,A C T I V E L E A R N I N G 1B: E

12、xercise,Now suppose the government cuts taxes by $200 billion. In each of the following two scenarios, determine what happens to public saving, private saving, national saving, and investment. 1.Consumers save the full proceeds of the tax cut. 2.Consumers save 1/4 of the tax cut and spend the other

13、3/4.,14,A C T I V E L E A R N I N G 1B: Answers,In both scenarios, public saving falls by $200 billion, and the budget deficit rises from $300 billion to $500 billion. 1. If consumers save the full $200 billion, national saving is unchanged, so investment is unchanged. 2. If consumers save $50 billi

14、on and spend $150 billion, then national saving and investment each fall by $150 billion.,15,A C T I V E L E A R N I N G 1: Calculate labor force statistics,Compute the labor force, u-rate, adult population, and labor force participation rate using this data:,16,0,A C T I V E L E A R N I N G 1: Answ

15、ers,Labor force = employed + unemployed= 146.0 + 7.8= 153.8 million U-rate= 100 x (unemployed)/(labor force)= 100 x 7.8/153.8= 5.1%,17,0,A C T I V E L E A R N I N G 1: Answers,Population= labor force + not in labor force= 153.8 + 79.2= 233.0 LF partic. rate= 100 x (labor force)/(population)= 100 x 1

16、53.8/233.0= 66.0%,18,0,A C T I V E L E A R N I N G 1: Exercise,While cleaning your apartment, you look under the sofa cushion find a $50 bill (and a half-eaten taco). You deposit the bill in your checking account. The Feds reserve requirement is 20% of deposits.,19,A.What is the maximum amount that

17、the money supply could increase? B.What is the minimum amount that the money supply could increase?,0,A C T I V E L E A R N I N G 1: Answers,If banks hold no excess reserves, then money multiplier = 1/R = 1/0.2 = 5 The maximum possible increase in deposits is 5 x $50 = $250 But money supply also inc

18、ludes currency, which falls by $50. Hence, max increase in money supply = $200.,20,You deposit $50 in your checking account. A.What is the maximum amount that the money supply could increase?,0,A C T I V E L E A R N I N G 1: Answers,Answer: $0 If your bank makes no loans from your deposit, currency

19、falls by $50, deposits increase by $50, money supply remains unchanged.,21,You deposit $50 in your checking account. A.What is the maximum amount that the money supply could increase? Answer: $200 B.What is the minimum amount that the money supply could increase?,0,A C T I V E L E A R N I N G 1: Exe

20、rcise,One good: corn. The economy has enough labor, capital, and land to produce Y = 800 bushels of corn. V is constant. In 2005, MS = $2000, P = $5/bushel. Compute nominal GDP and velocity in 2005.,22,0,A C T I V E L E A R N I N G 1: Answers,Given: Y = 800, V is constant, MS = $2000 and P = $5 in 2

21、005.,23,Compute nominal GDP and velocity in 2005.,0,A C T I V E L E A R N I N G 2: Exercise,One good: corn. The economy has enough labor, capital, and land to produce Y = 800 bushels of corn. V is constant. In 2005, MS = $2000, P = $5/bushel.,24,For 2006, the Fed increases MS by 5%, to $2100. a.Comp

22、ute the 2006 values of nominal GDP and P. Compute the inflation rate for 2005-2006. b.Suppose tech. progress causes Y to increase to 824 in 2006. Compute 2005-2006 inflation rate.,0,A C T I V E L E A R N I N G 2: Answers,Given: Y = 800, V is constant, MS = $2000 and P = $5 in 2005.,25,For 2006, the

23、Fed increases MS by 5%, to $2100. a.Compute the 2006 values of nominal GDP and P. Compute the inflation rate for 2005-2006.,Nominal GDP = P x Y,= M x V (Quantity Eqn),P =,=,Inflation rate =,0,A C T I V E L E A R N I N G 2: Answers,Given: Y = 800, V is constant, MS = $2000 and P = $5 in 2005.,26,For

24、2006, the Fed increases MS by 5%, to $2100. b.Suppose tech. progress causes Y to increase 3% in 2006, to 824. Compute 2005-2006 inflation rate.,First, use Quantity Eqn to compute P:,P =,=,= $5.10,Inflation rate =,0,A C T I V E L E A R N I N G 2: Summary & lessons about the Quantity Theory of Money,2

25、7,If real GDP is constant, then inflation rate = money growth rate. If real GDP is growing, theninflation rate money growth rate. The bottom line: Economic growth increases # of transactions. Some money growth is needed for these extra transactions. Excessive money growth causes inflation.,0,A C T I

26、 V E L E A R N I N G 3: Tax distortions,You deposit $1000 in the bank for one year. CASE 1: inflation = 0%, nom. interest rate = 10% CASE 2: inflation = 10%, nom. interest rate = 20% a.In which case does the real value of your deposit grow the most? Assume the tax rate is 25%. b.In which case do you

27、 pay the most taxes? c.Compute the after-tax nominal interest rate, then subtract off inflation to get the after-tax real interest rate for both cases.,28,0,A C T I V E L E A R N I N G 3: Answers,29,a.In which case does the real value of your deposit grow the most? In both cases, the real interest r

28、ate is 10%, so the real value of the deposit grows 10% (before taxes).,Deposit = $1000. CASE 1: inflation = 0%, nom. interest rate = 10% CASE 2: inflation = 10%, nom. interest rate = 20%,0,A C T I V E L E A R N I N G 3: Answers,30,b.In which case do you pay the most taxes? CASE 1: interest income =

29、$100, so you pay $25 in taxes. CASE 2: interest income = $200, so you pay $50 in taxes.,Deposit = $1000. Tax rate = 25%. CASE 1: inflation = 0%, nom. interest rate = 10% CASE 2: inflation = 10%, nom. interest rate = 20%,0,A C T I V E L E A R N I N G 3: Answers,31,c.Compute the after-tax nominal inte

30、rest rate, then subtract off inflation to get the after-tax real interest rate for both cases. CASE 1:nominal = 0.75 x 10% = 7.5% real = 7.5% 0% = 7.5% CASE 2:nominal = 0.75 x 20% = 15% real = 15% 10% = 5%,Deposit = $1000. Tax rate = 25%. CASE 1: inflation = 0%, nom. interest rate = 10% CASE 2: infl

31、ation = 10%, nom. interest rate = 20%,0,A C T I V E L E A R N I N G 3: Summary & lessons,32,Deposit = $1000. Tax rate = 25%. CASE 1: inflation = 0%, nom. interest rate = 10% CASE 2: inflation = 10%, nom. interest rate = 20%,Inflation raises nominal interest rates (Fisher effect) but not real interest rates increases savers tax burdens lowe