宏观经济学 课后答案 【美】奥利维尔·布兰查德 著

Chapter 1 1. a. True. b. True. c. False. d. True. e. False. f. False. 2. a. 1960-98 1997-99 ---------- --------- US 3.1% 3.8% EU 3.1% 2.5% Japan 5.8% -1.0% While the US growth rate higher than its long-run average over the period, the growth rate has slowed relative to long-run averages in both the EU and Japan over the last few years. b. Sometimes the economy is growing quickly, other times it is growing slowly or even contracting. The last few years of rapid growth in the US do not imply that the long-run average rate of growth has increased back to its pre-1974 level. 3. a. The data in the web page are: Real Gross Domestic Product,Real Final Sales of Domestic Product, andReal Gross National Product, Quarterly, 1959-96[Percent change from preceding quarter] -------------------------------------------------------- Gross Final sales Gross domestic of domestic national product product product ------------------------------------------------------- 1959: I 8.6 9.2 8.6 II 11.2 7.3 11.1 III -0.3 5.3 -0.2 IV 1.7 -1.3 1.9 1996: I 1.8 2.6 1.8 II 6.0 5.2 5.7 III 1.0 0.2 0.6 IV 4.3 4.5 4.9 -------------------------------------------------------- suggesting that recessions typically last two-three quarters and that the most severe recessions in that period were the recessions of 1974-75 and 1981-82. b. Percentage Changes in: Output Growth Inflation 1968: 4.7 4.4 I 7.5 4.7 II 7.1 4.1 III 3.0 3.8 IV 1.8 5.5 1969: 3.0 4.7 I 6.2 3.8 II 1.0 5.0 III 2.3 5.8 IV -2.0 5.1 1970: 0.1 5.3 I -0.7 6.0 II 0.6 5.7 III 3.7 3.4 IV -3.9 5.4 1971: 3.3 5.2 I 11.3 6.4 II 2.3 5.5 III 2.6 4.4 IV 1.1 3.3 If history simply repeats itself, the United States might have a short recession (lasting perhaps one year) accompanied by an acceleration in the rate of inflation by about one percentage point. 4. a. Banking services, business services. b. Not only has the relative demand for skilled workers increased but the industries where this effect is the strongest are making up a greater fraction of the economy. 5. 1. Low unemployment might lead to an increase in inflation. 2. Although measurement error certainly contributes to the measured slowdown in growth, there are other issues to consider as well, including the productivity of new research and accumulation of new capital. 3. Although labor market rigidities may be important, it is also important to consider that these rigidities may not be excessive, and that high unemployment may arise from flawed macroeconomic policies. 4. Although there were serious problems with regard to the management of Asian financial systems, it is important to consider the possibility that the flight of foreign capital from these countries worsened the situation by causing a severe stock market crash and exchange rate depreciation. 5. Although the Euro will remove obstacles to free trade between European countries, each country will be forced to give up its own monetary policy. * 6. a. From Chapter 1: US output 1997=$8b; China output 1996=$.84b. Note that China’s output in 1997 is $(.84)*(1.09) b. Equating output for some time t in the future: 8*(1.03)t=(.84*1.09)*(1.09)t 8/(.84*1.09)=(1.09/1.03)t 8.737=(1.058)t t =ln(8.737)/ln(1.058) ≈38yrs b. From Chapter 1: US output/worker in 1997=$29,800; China output/per worker in 1996=$700 29.8*(1.03)t=(.7*1.09)*(1.09)t t≈65 years Chapter 2 1. a. False. b. Uncertain: real or nominal GDP. c. True. d. True. e. False. The level of the CPI means nothing. Its rate of change tells us about inflation. f. Uncertain. Which index is better depends on what we are trying to measure—inflation faced by consumers or by the economy as a whole. 2. a. +$100; Personal Consumption Expenditures b. nochange:intermediategood c. +$200 million; Gross PrivateDomesticFixedInvestment d. +$200 million; Net Exports e. no change: the jet was already counted when it was produced, i.e., presumably when Delta(or some other airline) bought it new as an investment. *3. a. Measured GDP increases by $10+$12=$22. b. True GDP should increase by much less than $22 because by working for an extra hour, you are no longer producing the work of cooking within the house. Since cooking within the house is a final service, it should count as part of GDP. Unfortunately, it is hard to measure the value of work within the home, which is why measured GDP does not include it. 4. a. $1,000,000 the value of the silver necklaces. b. 1st Stage:$300,000.2ndStage:$1,000,00-$300,000=$700,000. GDP: $300,000+$700,000=$1,000,000. c. Wages: $200,000 + $250,000=$450,000. Profits: ($300,000-$200,000)+($1,000,000-$250,000-300,000) =$100,000+$450,000=$550,000. GDP:$450,000+$550,000=$1,000,000. 5. a. 1998 GDP: 10*$2,000+4*$1,000+1000*$1=$25,000 1999 GDP: 12*$3,000+6*$500+1000*$1=$40,000Nominal GDP has increased by 60%. b. 1998 real (1998) GDP: $25,000 1999 real (1998) GDP: 12*$2,000+6*$1,000+1000*$1=$31,000 Real (1998) GDP has increased by 24%. c. 1998 real (1999) GDP: 10*$3,000+4*$500+1,000*$1=$33,000 1999 real (1999) GDP: $40,000.Real (1999) GDP has increased by 21.2%. d. True. 6. a. 1998 base year:Deflator(1998)=1; Deflator(1999)=$40,000/$31,000=1.29 Inflation=29% b. 1999 base year:Deflator(1998)=$25,000/$33,000=0.76; Deflator(1999)=1 Inflation=(1-0.76)/0.76=.32=32% c. Yes 7. a. 1998 real GDP = 10*$2,500 + 4*$750 + 1000*$1 = $29,000 1999 real GDP = 12*$2,500 + 6*$750 + 1000*$1 = $35,500 b. (35,500-29,000)/29,000 = .224 = 22.4% c. Deflator in 1998=$25,000/$29,000=.86Deflator in 1999=$40,000/$35,500=1.13 Inflation = (1.13 -.86)/.86 = .314 = 31.4%. 8. a. The quality of a routine checkup improves over time. Checkups now may include EKGs, for example. Medical services are particularly affected by this problem due to constant improvements in medical technology. b. You need to know how the market values pregnancy checkups with and without ultra-sounds in that year. c. This information is not available since all doctors adopted the new technology simultaneously. Still, you can tell that the quality adjusted increase will be lower than 20%. *9. a. approximately 2.5% b. 1992 real GDP growth: 2.7%; unemployment rate Jan 92: 7.3%; unemployment rate Jan 93: 7.3% Supports Okun's law because the unemployment rate does not change when the growth rate of real GDP is near 2.5% c. -2 percentage points change in the unemployment rate; 5 percent GDP growth d. The growth rate of GDP must increase by 2.5 percentage points. Chapter 3 1. a. True. b. False. Government spending was 18% if GDP without transfers. c. False. The propensity to consume must be less than one for our model to be well defined. d.True. false. f. False. The increase in output is one times the multiplier. 2. a. Y=160+0.6*(Y-100)+150+150 0.4Y=460-60 Y=1000 b. YD=Y-T=1000-100=900 c. C=160+0.6*(900)=700 3. a. No. The goods market is not in equilibrium. From part 2a, Demand=1000=C+I+G=700+150+150 b. Yes. The goods market is in equilibrium. c. No. Private saving=Y-C-T=200. Public saving =T-G=-50. National saving (or in short, saving) equals private plus public saving, or 150. National saving equals investment. 4. a. Roughly consistent. C/Y=700/1000=70%; I/Y=G/Y=150/1000=15%. b. Approximately -2%. c. Y needs to fall by 2%, or from 1000 to 980. The parameter c0 needs to fall by 20/multiplier, or by 20*(.4)=8. So c0 needs to fall from 160 to 152. d. The change in c0 (-8) is less than the change in GDP (-20) due to the multiplier. 5. a. Y increases by 1/(1-c1) b. Y decreases by c1/(1- c1) c. The answers differ because spending affects demand directly, but taxes affect demand through consumption, and the propensity to consume is less than one. d. The change in Y equals 1/(1-c1) - c1/(1- c1) = 1. Balanced budget changes in G and T are not macroeconomically neutral. e. The propensity to consume has no effect because the balanced budget tax increase aborts the multiplier process. Y and T both increase by on unit, so disposable income, and hence consumption, do not change. *6. a. The tax rate ilessthanone.b. Y=c0+c1YD+I+G implies Y=[1/(1-c1+c1t1)]*[c0-c1t0+I+G] c. The multiplier = 1/(1-c1+c1t1) <1/(1- c1), so the economy responds less to changes in autonomous spending when t1 is positive. d. Because of the automatic effect of taxes on the economy, the economy responds less to changes in autonomous spending than in the case where taxes are independent of income. So output tends to vary less, and fiscal policy is called an automatic stabilizer. *7. a. Y=[1/(1-c1+c1t1)]*[c0-c1t0+I+G] b. T = c1t0 + t1*[1/(1-c1+c1t1)]*[c0-c1t0+I+G] c. Both Y and T decrease. d. If G is cut, Y decreases even more. Chapter 4 1. a.True. b.Fals. c.True. d.True. e.False. f.False. g.True. 2. a. i=0.05: Money demand = $18,000; Bond demand = $32,000 i=.1: Money demand = $15,000; Bond demand = $35,000 b. Money demand decreases when the interest rate increases; bond demand increases. This is consistent with the text.c. The demand for money falls by 50%. d. The demand for money falls by 50%. e. A 1% increase (decrease) in income leads to a 1% increase (decrease) in money demand. This effect is independent of the interest rate. 3. a. i=100/$PB –1; i=33%; 18%; 5% when $PB =$75; $85; $95. b. Negative. c. $PB =100/(1.08)≈$93 4. a. $20=MD=$100*(.25-i) i=5% b. M=$100*(.25-.15) M=$10 5. a. BD = 50,000 - 60,000 (.35-i) An increase in the interest rate of 10% increases bond demand $6,000. b. An increase in wealth increases bond demand, but has no effect on money demand. c. An increase in income increases money demand, but decreases bond demand. d. When people earn more income, this does not change their wealth right away. Thus, they increase their demand for money and decrease their demand for bonds. 6. a. Demand for high-powered money=0.1*$Y*(.8-4i) b. $100 b = 0.1*$5,000b*(.8-4i) i=15% c. M=(1/.1)*$100 b=$1,000 b M= Md at the interest derived in part b. 6. d. If H increases to $300, falls to 5%. e. M=(1/.1)*$300 b=$3,000 b 7. a. $16 is withdrawn on each trip to the bank. Money holdings—day one: $16; day two: $12; day three: $8; day four: $4. b. Average money holdings are $10. c. $8 dollar withdrawals; money holdings of $8; $4; $8; $4. d. Average money holdings are $6. e. $16 dollar withdrawals; money holdings of $0; $0; $0; $16. f. Average money holdings are $4. g. Based on these answers, ATMs and credit cards have reduced money demand. 8. a. velocity=1/(M/$Y)=1/L(i) b. Velocity roughly doubled between the mid 1960s and the mid 1990s. c. ATMS and credit cards reduced L(i) so velocity increased. Chapter 5 1. a.Trub.Tru c.Fal. d. False. The balanced budget multiplier is positive (it equals one), so the IS curve shifts right.e. False. f. Uncertain. An increase in G leads to an increase in Y (which tends to increase investment), but an increase in the interest rate (which tends to reduce investment). g. True. *2. Firms deciding how to use their own funds will compare the return on bonds to the return on investment. When the interest rate on bonds increases, they become more attractive, and firms are more likely to use their funds to purchase bonds, rather than to finance investment projects. a.Y=[1/(1-c1)]*[c0-c1T+I+G] The multiplier is 1/(1-c1). b. Y=[1/(1-c1-b1)]*[c0-c1T+ b0-b2i +G] The multiplier is 1/(1-c1-b1). Since the multiplier is larger than the multiplier in part a, the effect of a change in autonomous spending is bigger than in part a. c. Substituting for the interest rate in the answer to part b: Y=[1/(1-c1-b1+ b2d1/d2)]*[c0-c1T+ b0+(b2*M/P)/d2 +G]The multiplier is 1/(1-c1-b1+ b2d1/d2). d. The multiplier is greater (less) than the multiplier in part a if (b1- b2d1/d2) is greater (less) than zero. The multiplier is big if b1 is big, b2 is small, d1 is small, and/or d2 is big, i.e., if investment is very sensitive to Y, investment is not very sensitive to i, money demand is not very sensitive to Y, money demand is very sensitive to i. 4. a. The IS curve shifts left. Output and the interest rate fall. The effect on investment is ambiguous because the output and interest rate effects work in opposite directions: the fall in output tends to reduce investment, but the fall in the interest rate tends to increase it. b. From 3c: Y=[1/(1-c1-b1)]*[c0-c1T+ b0-b2i +G]c. From the LM relation: i= Y*d1/d2 – (M/P)/d2To obtain the equilibrium interest rate, substitute for Y from part b. d. I= b0+ b1Y- b2i= b0+ b1Y- b2Y* d1/d2+ b2(M/P)/d2 To obtain equilibrium investment, substitute for Y from part b. e. Holding M/P constant, I increases with equilibrium output when b1>b2 d1/d2. Since a decrease in G reduces output, the condition under which a decrease in G increases investment is b15, repeated substitution implies, t=5+(t-5)*4%. So, 10=28%; 15=48%. f. Inflation expectations will again be forever wrong. This is unlikely. 4. a. t=t-1 + 0.1 - 2ut=t-1 + 2% t =2%; t+1=4%; t+2=6%; t+3=8%. b. t=0.5t + 0.5t-1 + 0.1 - 2ut or, t=t-1 + 4% 4. c. t =4%; t+1=8%; t+2=12%; t+3=16% d. As indexation increases, low unemployment leads to a larger increase in inflation ove