宏觀經(jīng)濟(jì)學(xué)第七版答案曼昆

Answers to Selected Student Guide Problems* *Note to instructors: The answers to most of the data questions were taken from the 2009 Economic Report of the President.Some data for 2008 were taken from the Bureau of Economic Analysis and Department of Labor websites. The data may be revised in later publications Data QuestionsData Questions 1. a.The following 2008 data, in billions of dollars, were obtained from the Bureau of Economic Analysis Web site at /. The data may be revised in future publications. T Ta ablble e 2727 (1)(2) Gross Domestic Product$14,264.6 EQUALS Consumption$10,057.9 +Investment$ 1,993.5 +Government Purchases of Goods and Services$ 2,882.4 +Exports$ 1,859.4 Imports$ 2,528.6 b.GDP = $10,057.9 + $1,993.5 + $2,882.4 $669.2 = $14,264.6 (billion) 2. a. T Ta ablble e 2828 (1)(2)(3)(4)(5) % Change% Change in CPI fromGDPin GDP Deflator from YearCPIPreceding YearDeflatorPreceding Year 2007207.34119.82 3.82.2 2008215.30122.50 b. Imported oil is not part of U.S. GDP. Therefore, it is not included in the calcula- tion of the GDP deflator, although it is included in the calculation of the CPI when it is purchased by consumers. Because the United States imports, rather than produces, a large portion of the oil households consume, the oil price increase had a greater effect on the CPI than on the GDP deflator from 2007 to 2008. 203 C H A P T E R2The Data of Macroeconomics 3. a. T Ta ablble e 2929 (1)(2)(3)(4)(5) % Change Total U.S.in Real GDP Real GDPPopulationReal GDPper Capita from Year($ in billions)(in millions)per CapitaPreceding Decade 19785,015222.6$22,530 22.2 19886,743245.0$27,522 19.3 19989,067276.1$32,840 16.7 200811,652304.1$38,316 b.U.S. real GDP per capita grew the fastest from 1978 to 1988; it grew the slowest from 1998 to 2008. 4. a. and c. T Ta ablble e 210210 (1)(2)(3)(4)(5)(6)(7) GDP% ChangeReal% ChangeNominal% Change YearDeflator (P)in PGDP (Y)in YGDP (Y)in PY ($ in billions)($ in billions) 2007119.8211,52413,808 2008122.5011,65214,265 b.3.3 ProblemsProblems 10. a.The costs of expected inflation are the shoeleather costs of inflation, the menu costs of changing prices, the cost of unindexed taxes, the cost of greater variability in prices, and the costs to people who receive incomes fixed in nominal terms (such as private pensions) that were contracted before the inflation was expected. b.Although federal income taxes are now indexed for inflation, taxes on capital gains and interest income are not. Consequently, if inflation were to fall from 2 percent to 0 percent and, according to the Fisher effect, nominal interest rates were to fall by 2 percentage points, the after-tax real return to saving and invest- ment would increase. c.3 percent, assuming a constant velocity of money d.Expected inflation would fall; the nominal interest rate would fall; real money demand would increase by more than the 3-percent growth in output; real money balances would increase by the same amount; the price level would fall; actual inflation would temporarily be negative. e.With 0 percent inflation, real wages can fall only if nominal wages decline, and workers vigorously resist reductions in nominal wages. 204Answers to Selected Student Guide Problems C H A P T E R4Money and Inflation Data QuestionsData Questions 1. a. T Ta ablble e 4949 (1)(2)(3)(4)(5)(6)(7) Consumer Price Indices CPICPI All%Medical%CPI% YearItemsChangeCareChangeEnergyChange 197865.261.852.5 81.4124.370.0 1988118.3138.689.3 37.874.715.2 1998163.0242.1102.9 32.150.4130.0 2008215.3364.1236.7 b.$8.49 c.1978 to 1988 d.1998 to 2008 e.The OPEC oil shock in 1979 and the most recent shocks from 2002 to 2005 and in 2008 account for the increase in the relative price of oil during those periods. 2. a. T Ta ablble e 410410 (1)(2)(3)(4)(5)(6)(7)(8) Nominal% Change M1(Dec.)M2(Dec.) GDP($ inGDPin GDP($ in% Change($ in % Change Yearbillions)Deflator Deflatorbillions)in M1billions)in M2 19782,29545.83571,366 65.3120.4119.2 19885,10475.77872,994 27.539.346.2 19988,74796.51,0964,378 26.945.686.2 200814,265122.51,5968,154 b.If the long-run growth rate of real GDP is 3 percent per year, or about 34 percent per decade, and velocity were constant, the quantity theory would predict that = % Change in M 34% per decade. If we use M1 as our measure of the money supply, the simple quantity theory pre- dicts 10-year inflation rates of 86.4 percent from 1978 to 1988; 5.3 percent from 1988 to 1998, and 11.6 percent from 1998 to 2008. c.Using M1, the quantity theory is a fairly good predictor of inflation in the first and third decades and a poor predictor in the middle decade. d.If we use M2 as our measure of the money supply, the simple quantity theory pre- dicts 10-year inflation rates of 85.2 percent, 12.2 percent, and 52.2 percent for the three decades, respectively. It is a fairly good predictor for the first two decades, but not for the most recent decade. 3. a. V for M2 in 1978 = 1.68; V for M2in 2008 = 1.75; obviously, M2 velocity has risen a bit, contrary to the assumption of the simple quantity theory, but not much. Chapter4Money and Inflation205 b.V for M1 in 1978 = 6.43, V for M1 in 2008 = 8.94; M1 velocity has risen a lot, con- trary to the assumption of the simple quantity theory. c.Even if velocity changes, MV= PYand the % change in M+ % change in V approximately equals the % change in P + % change in Y. Thus, if both velocity and real GDP change steadily over time, % change in P= % change in M+ % change in Y % change in V, and any increase in the money supply will be accom- panied by an equal increase in the price level. ProblemsProblems 11. a.If the deficit were eliminated, public saving would rise. If taxes were cut, in the long run private saving would also rise. Thus, national saving would rise. b.In a closed economy, the S curve shifts right (as saving increases), the real rate of interest falls, and the amount of investment increases although the investment curve does not shift: Graph for Problem 11(b) 206Answers to Selected Student Guide Problems C H A P T E R5The Open Economy I1 = I2 r r1 r2 Real interest rate 0 Investment, Saving I, S S1S2 c.Graph for Problems 11(c) and 11(d) d.Treating the United States as a small open economy, we once again shift the S curve to the right as national saving increases. The real interest rate, however, remains fixed at r*. Consequently, investment does not change, but S I increases. e.As the S I curve shifts right below, the U.S. real exchange rate falls and net exports rise. Graph for Problem 11(e) Chapter5The Open Economy207 r* = 2.5% (S I)1(S I)2 NX S I, NX+0 2 1 17. The initial equilibrium is represented by points A in panels (A), (B), and (C) below. Graph for Problem 17 The reduction in taxes and government spending would increase national saving and shift the S curve right to S2in panel (A). The I + CF curve would not shift, so the domestic real interest rate would fall to point B. Consequently, the level of net capital outflow would rise in panel (B). Since net capital outflow equals the trade surplus, the latter would also rise, implying a decrease in the trade deficit. As NX rises, the real exchange rate will fall. As the domestic real interest rate falls, investment will rise. Data QuestionsData Questions 1. a.T Ta ablble e 5858 (1)(2)(3)(4)(5)(6) Exports ofImports of NominalGoods andExports asGoods andImports as GDP ($ inServices% ofServices% of Yearbillions)($ in billions)Nominal GDP($ in billions) Nominal GDP 19782,295186.98.1212.39.3 19936,657655.89.9720.910.8 200814,2651,859.413.02,528.617.7 208Answers to Selected Student Guide Problems Panel anel B B A B A CF CFS , I + CF I + CF S1S2 r rA rB Panel C B A NX NX CFrACFrB PA r 0+ 0+ A B b. increased; more c.T Ta ablble e 5959 (1)(2)(3) Net Exports of GoodsNet Exports as Yearand Services ($ in billions)% of Nominal GDP 197825.41.1 199365.11.0 2008669.24.7 d.25.4; 25.4 e.669.2; 669.2 3. a.The Western European natural rate of unemployment in the 1960s was 2.5 per- cent, compared with the U.S. natural rate in the textbook of 4.76 percent. b.8 percent 6. a.E/POP = E/L L/POP, where POP = the noninstitutional population. b.E/POP indicates the portion of the population that has a job. In a healthy econo- my, this will be large. Furthermore, many of the unemployed may not really want to work at the jobs that are available to them. While it may be difficult to measure true unemployment accurately, it is easier to measure E and POP. c.The unemployment rate represents the portion of those who desire to work who cannot find work. Even if the employment-to-population ratio is high, a high unemployment rate will signify an economy that is producing much less than its potential. Furthermore, if leisure is a normal good, the goal of society should be a low employment-to-population ratio coupled with a low unemployment rate. Data QuestionsData Questions 1. a.T Ta ablble e 6262 Labor-Force Participation Rates (in percent) (1)(2)(3)(4) Male and Female YearTotal CivilianCivilian MalesCivilian Females 196859.680.141.6 198865.976.256.6 200866.073.059.5 b.The labor-force participation rate among civilian females has increased as more married women have entered the labor market. The labor-force participation rate among civilian males has fallen because of earlier retirement and greater disabili- ty, among other reasons. Chapter6Unemployment209 C H A P T E R6Unemployment c.Real GDP has risen by the amount of extra output women produce in their new jobs. “Total production” does not rise as much as measured real GDP because the reduction in household production that was formerly performed by these women must be subtracted from the extra output produced in paid employment, especial- ly between 1968 and 1988. If we consider the fact that many of these women now pay others to do some of this household production, the difference between the change in real GDP and the change in “total production” is even greater. 2. a.The median of a group of numbers is the “middle” number. Half of the numbers are greater than the median, and half are less than the median. The mean or average is equal to the sum of all the numbers divided by the number of numbers. b.The median duration of unemployment in 2008 was 9.4 weeks. The mean dura- tion of unemployment in 2008 was 17.9 weeks. c.Unemployment in the United States is characterized by many short spells and a smaller number of very long spells. Hence, the median duration of unemployment is much smaller than the mean duration. 3. a., b., and c. T Ta ablble e 6363 (1)(2)(3)(4)(5) InflationConventionalNew UnemploymentRateMiseryMisery YearRate(Year to Year)IndexIndex 20064.6%3.2%7.811.0 20074.6%2.8%7.410.6 20085.8%3.8%9.613.7 d.Economic suffering increased more rapidly in 2008 using the new misery index, and even more so in 2009. Data QuestionsData Questions 1. a.Approximate Average Annual Percentage Growth Rates of Real GDP 1990199920002008 United States3.12.4 Japan1.51.6 Germany2.31.5 China9.99.9 India5.67.2 Africa2.35.5 b.In the year 2038 210Answers to Selected Student Guide Problems C H A P T E R7Economic Growth I ProblemsProblems 4. The short-run aggregate supply curve would shift downward, while the aggregate demand curve would be unaffected. Output would rise, and the aggregate price level would fall. Data QuestionsData Questions 1. a.Table 94Table 94 (1)(2)(3) 19791982% Change (in 1,000s)(in 1,000s)19791982 Civilian noninstitutional population164,863172,2714.5 Civilian labor force104,962110,2045.0 Civilian employment98,82499,5260.7 Civilian unemployment6,13710,67874.0 b.During recessions, employment grows by a smaller rate than the labor force. Consequently, unemployment grows by a much larger rate than either employ- ment or the labor force. During economic recoveries, the reverse is true. The popu- lation grows at a more constant rate over time, although it, too, is affected by eco- nomic conditions in the long run. c.The actual unemployment rate would eventually have equaled 5.8 percent. 2. In April 2009, the unemployment rate was 8.9 percent. If the unemployment rate for all of 2009 was 8.9 percent, Okuns law would predict that the real GDP would fall by 3.2 percent. ProblemsProblems 4. a.0.75 b.Graph for Problem 4(b) slope of C = 0.6; y intercept = 20 Chapter9Introduction to Economic Fluctuations211 C H A P T E R9Introduction to Economic Fluctuations C H A P T E R10Aggregate Demand I 20 C C Y Income, output 0 Consumption slope of PE = 0.6; y intercept = 800 c.2,000 d.0 e.The government-purchases multiplier is 2.5. When G rises, the multiplier is smaller than 1/(1 MPC) because any increase in income will be accompanied by an increase in taxes. Hence, the increase in disposable income in each round will be smaller than the increase in income. Alternatively, the slope of the planned expenditure curve becomes MPC(1 t), where t equals the income tax rate. Hence, the multiplier becomes 1/1 MPC(1 t). 6. a.Planned investment might increase as Y rises (leading to the positively sloped line below) if investment depends on profits or sales expectations (along with r) and either or both of these rise along with Y. b.i. The slope of the planned-expenditure curve would increase. ii. The government-purchases multiplier would increase. iii.The IS curve would be flatter, and the LM curve would be unaffected. 212Answers to Selected Student Guide Problems PE PE Y Income, output 0 Planned expenditure 800 0Y I I Income, output I Planned investment Data QuestionsData Questions 1.T Ta ablble e 107107 (1)(2)(3)(4)(5)(6) Nominal M2 in December% Change in GDP DeflatorReal M2% Change Year($ in billions)M2(2000 = 100)M2/Pin M2/P 19791,473.749.52,977.2 8.60.5 19801,599.854.02,962.6 9.70.3 19811,755.459.12,970.2 8.82.6 19821,910.162.73,046.4 11.37.1 19832,126.465.23,261.3 The LMcurve implies that changes in the real money supply are the appropriate measures of monetary conditions. Using this measure, the Fed pursued mildly contractionary monetary policy between 1979 and 1980, neutral policy between 1980 and 1981, expansionary policy between 1981 and 1982, and very expansion- ary policy between 1982 and 1983. A better measure might be changes in the real money supply in excess of the long-run growth rate of natural GDP of 3 per- cent. Using this measure, monetary policy was contractionary during the first three periods and expansionary in the fourth. ProblemsProblems 4. a.The deficit would fall. The IS curve would shift to the left. Graph for Problem 4(a) As a result, the interest rate would fall, but so would real GDP. This last change is contrary to some economists predictions. Chapter10Aggregate Demand I213 C H A P T E R11Aggregate Demand II r 0 r1 r2 LM IS2 IS1 Real interest rate Income, output YY2Y1 b.If expansionary monetary policy is pursued simultaneously, the interest rate and the deficit will still fall and real income may actually rise. Graph for Problem 4(b) c.In part (a), the aggregate demand curve shifts left. In part (b), the aggregate demand curve shifts right if Y rises. 13. a.Graph for Problem 13(a) b.If r is on the vertical axis, the IS curve will not shift in response to a change in expected inflation, but the LM curve will shift upward by 10 percentage points. Consequently, i and Y fall and r rises. Although the graph is different from the one in the textbook because r is now on the vertical axis, the changes to Y, i, and r are the same. 14.If the money supply M increased as the interest rate increased, the money supply curve would be upward sloping. 214Answers to Selected Student Guide Problems 0 r2 Y IS1 IS2 Income, output r Real interest rate LM1 LM2 r1 Y1Y2 Income, output A Y IS r r2 r1 Y1Y2 LM1(e = 0) LM2(e = 10) r1 + 10 0 Real Interest Rate Graph for Problem 14 Consequently, an increase in income that increases the demand for real money balances would increase the interest rate and the money supply. The increase in the interest rate would be less than when M is independent of the interest rate, resulting in a flatter LM curve. Data QuestionsData Questions 1. a. T Ta ablble e 111111 (1)(2)(3)(4)(5)(6)(7) Real GDP%M1GDP% in billions ofChange inin Dec.DeflatorReal M1 Change in Year2000 dollarsReal GDP ($ in billions) (2000 = 100) (= M1/P)Real M1 19795,173.4381.849.5771.3 0.21.9 19805,161.7408.554.0756.5 2.52.3 19815,291.7436.759.1738.9 1.92.5 19825,189.3474.862.7757.3 b.The reduction in real GDP was much greater during the Great Depression, even though the reduction in real money balances from 1929 to 1933 was smaller than during the 19791981 period. 2.a. T Ta ablble e 112112 (1)(2)(3)(4) Real GDP%Interest Rate in billions ofChange inon 10-Year U.S. Year2000 dollarsReal GDPTreasury Securities 19602,501.84.12 27.6 19653,191.14.28 Chapter11Aggregate Demand II215 B A B A LM Y M/P r r2 r2 r1 C L1(Y = Y1) L2(Y2) (M/P) (M/P) Real money balances 0 Real interest rate C LM Y1Y2 Income, output 0 Real interest rate r r2 r2 r1 b.Since the interest rate remained relatively constant while real GDP rose, it may be presumed that both the LMand the IScurves shifted to the right and that the horizontal shift was the same for both curves. Consequently, the Federal Reserve must have increased the money supply during this period. Data QuestionsData Questions 1. a. and b. T Ta ablble e 131131 (1)(2)(3)(4)(5)(6) Real GDPActualPredicted (billions%CivilianChange inChange in of 2000Change inUnemploymentUnemploymentUnemployment Yeardollars)Real GDPRate (%)RateRate 20019,890.74.7 1.6+1.1+0.7 200210,048.85.8 2.5+0.2+0.25 200310,301.06.0 200410,675.95.5 2.90.4+0.05 200510,989.55.1 c.Okuns law was fairly accurate during this period. ProblemsProblems 6. a.If capital gains taxes are reduced, the after-tax return to saving would increase. This might increase total saving, which would spur additional investment in a clo