武汉大学试卷习题西方经济学试题（A卷）及参考答案（2007.7.6）.pdf_大学文库

武汉大学经济与管理学院《西方经济学》议题(A卷)2007年7月6日主讲：陈忠城审核：姓名：学号：分数： 1.What is the difference between the aggregate supply and aggregate demand model used in macroeconomics and microeconomics?(Score:15) 2.Suppose an economy's real GDP is $30,000 in year I and $31,200 in year 2.What is the growth rate of its real GDP?Assume that population was 100 in year I and 102 in year 2.What is the growth rate of GDP per capita?(Score:15) 3.Assume the consumption schedule for a private open economy is such that C=50+08Y.Assume firther that plamned investment and net exports are independent of the level of income and comstant at 30 and10.Recall also that in equlibrium the real output produced (Y)is equal to the aggregate expenditures:Y-C (a)Calculate the equilibrium level of income for this ecoomy. (b)What will happen to equilibrium y if l changes to 10?What does this tell you about the size of the multiplier?(Score:15) 4.Why is each of the following incorrect?State the correct proposition.(Score:15) a)Marginal reverue product is calculated as total revenue eamed per worker. b)Under competition,workers get paid the total outp produced minus the costs ofraw materials 5.Draw the supply and demand curves for the oil market..Now suppose that a workable electric car shifts demand away from oil.Draw the new demand curve and the new equilibrium.Describe the oucome in terms of the price of o,the quantity consumed,and the total income of the oil producers. 6 Using the supply and demand aralysis of interest.explain how each of the following would affect interest rates in eapital theory:(Score:15) a.An innowation that increased the marginal product of capital at each level of capital. h.A decrease in the desired wealth holdings of households. e.A 50 pereent tac on the retur on capial (in the short run) 7.What is compurative advantage?Suppose thatTom produce half kilogram beef and two kilogram potatoes per hour.Jerry produces 1.5 kilogram beef and 3 kilogram potatoes per hour.Who should PF文件使用"pdfFactory Pro”试用版本创建w.finsprint,n

1 武汉大学经济与管理学院《西方经济学》试题(A 卷) 2007 年 7 月 6 日主讲：陈忠斌审核：姓名: 学号: 分数: 1、What is the difference between the aggregate supply and aggregate demand model used in macroeconomics and microeconomics？（Score:15） 2、Suppose an economy’s real GDP is $30,000 in year 1 and $31,200 in year 2. What is the growth rate of its real GDP? Assume that population was 100 in year 1 and 102 in year 2. What is the growth rate of GDP per capita?（Score:15） 3、Assume the consumption schedule for a private open economy is such that C = 50 + 0.8Y. Assume further that planned investment and net exports are independent of the level of income and constant at Ig = 30 and Xn = 10. Recall also that in equilibrium the real output produced (Y) is equal to the aggregate expenditures: Y = C + Ig + Xn . (a) Calculate the equilibrium level of income for this economy. (b)What will happen to equilibrium Y if Ig changes to 10? What does this tell you about the size of the multiplier? （Score:15） 4、Why is each of the following incorrect? State the correct proposition. （Score:15） a) Marginal revenue product is calculated as total revenue earned per worker. b) Under competition, workers get paid the total output produced minus the costs of raw materials. 5、Draw the supply and demand curves for the oil market.. Now suppose that a workable electric car shifts demand away from oil. Draw the new demand curve and the new equilibrium. Describe the outcome in terms of the price of oil, the quantity consumed, and the total income of the oil producers. 6.. Using the supply and demand analysis of interest, explain how each of the following would affect interest rates in capital theory: （Score:15） a. An innovation that increased the marginal product of capital at each level of capital. b. A decrease in the desired wealth holdings of households. c. A 50 percent tax on the return on capital (in the short run) 7、What is comparative advantage? Suppose thatTom produce half kilogram beef and two kilogram potatoes per hour. Jerry produces 1.5 kilogram beef and 3 kilogram potatoes per hour. Who should PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.cn

武汉大学经济与管理学院《西方经济学》(A卷)参考答案2007年7月6日 1,观经济学的总供给和总需求模型看起米、听起米都与微观经济学的标准供求模型极为相似。它们是否有联系？What is the d小ference between the aggregate supp吵y and aggregate demand model used in macrocconomics and microeconomics?(15) 1.The aggregate supply and aggregate demand model used in macroeconomics is not very similar to the market demand and market supply model used in microcconomics.While the workings of both models (the distinction between shifts of the curves versus movement along the curves)are similar.these models are really unrelated The "P*in the microeconomic model stands for the relative price of a good (or the ratio at which two goods are traded).whercas the "p"in the macroeconomic model stands for the average price level of all goods and services produced in this country.measured in money terms. 2、假设某一经济体的实际GDP第一年为3万美元，第二年为3.12万美元.求实际GDP的增长率？再假设第一年的人口为100，第二年的人口为102，求人均GDP的增长率？(Suppose an cconomy's real GDP is $30,000 in year 1 and $31,200 in year 2.What is the growth rate of'its real GDP?Assume that population was 100 in year I and 102 in year 2.What is the growth rate of GDP per capita2)(15分) Growth rate of real GDP =4 percent (=$31,200 -$30.000)$30.000).GDP per capita in year 1 -s300(-30,000W100).GDP per capita in3ear2-s305.88(-$31,200/102)Growth rate of GDP per capita is 1.96 percent =(5305.88-$300)300). 3.Assume the corsumption schedule for a private open economy is such that C=50+0.8y.Assume further that planned investment and net exports are independent of the level of income and constamt at l-30 andn10.Recall also that in equilibrium the real output produced (Y) is equal to the aggregate expenditures:Y'=C+/g+ a Calculate the equilibrium level of income for this economy.Check your work by expressing the comsumption,investment,and net export schedules in tabular form and determining the equilibrium GDP b What will happen to equilibrium Y'if le changes to 10?What does this tell you about the size of the multiplicr? 答3：Answers:(a 、(a).Y=C+I2+X.=s50+0.8T+530+s10=0.8r+390. 0.2Y=s90,→Y=$450 the equilibrium level of income for this economy is $450. 3 PF文件使用"pdfFactory Pro”试用版本创建w.fineprint.n

3 武汉大学经济与管理学院《西方经济学》(A 卷)参考答案 2007 年 7 月 6 日 1. 宏观经济学的总供给和总需求模型看起来、听起来都与微观经济学的标准供求模型极为相似，它们是否有联系？What is the difference between the aggregate supply and aggregate demand model used in macroeconomics and microeconomics？（15 分）答：1. The aggregate supply and aggregate demand model used in macroeconomics is not very similar to the market demand and market supply model used in microeconomics. While the workings of both models (the distinction between shifts of the curves versus movement along the curves) are similar, these models are really unrelated. The "P" in the microeconomic model stands for the relative price of a good (or the ratio at which two goods are traded), whereas the "P" in the macroeconomic model stands for the average price level of all goods and services produced in this country, measured in money terms. 2、假设某一经济体的实际 GDP 第一年为 3 万美元，第二年为 3.12 万美元。求实际 GDP 的增长率？再假设第一年的人口为 100，第二年的人口为 102。求人均 GDP 的增长率？（Suppose an economy’s real GDP is $30,000 in year 1 and $31,200 in year 2. What is the growth rate of its real GDP? Assume that population was 100 in year 1 and 102 in year 2. What is the growth rate of GDP per capita?）（15 分）答：Growth rate of real GDP = 4 percent (= $31,200 - $30,000)/$30,000). GDP per capita in year 1 = $300 (= $30,000/100). GDP per capita in year 2 = $305.88 (= $31,200/102). Growth rate of GDP per capita is 1.96 percent = ($305.88 - $300)/300). 3、Assume the consumption schedule for a private open economy is such that C = 50 + 0.8Y. Assume further that planned investment and net exports are independent of the level of income and constant at Ig = 30 and Xn = 10. Recall also that in equilibrium the real output produced (Y) is equal to the aggregate expenditures: Y = C + Ig + Xn . a Calculate the equilibrium level of income for this economy. Check your work by expressing the consumption, investment, and net export schedules in tabular form and determining the equilibrium GDP. b What will happen to equilibrium Y if Ig changes to 10? What does this tell you about the size of the multiplier? 答 3：Answers: (a) 0.2 $90, $450. ( ).. $50 0.8 $30 $10 0.8 $90, = Þ = = + + = + + + = + Y Y a Y C I g Xn Y Y the equilibrium level of income for this economy is $450. PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.cn

(b)If decreases from $30 to $10.the new equilibrium GDP will be at GDP of $350.for with /p now $10 this is where AE also equals $350.This indicates that the multiplier equals 5,for a decline in AE of $20 has led to a decline in equilibrium GDP of $100. The size of the multiplier could also have been eakulated directly from the MPC of 0.8 4.Chapter12-question4.Why is each of the following incerrect?State the correct proposition. (Samuelson,18"edition-chapter12.p242.) c) Marginal revenue product is calculated as total revenue earned per worker(MRP is the additional revenue produced by an additional unit of input) d)Distribution theory is simple.You simply figure out how much each factor produces and then give the factor its share of output.(Input contributions to production are interdependent,so it is impossible to determine what factor produced how much.) Under competition workers get paid the toal output produced minus the costs of raw materials.(If all factors are paid according to their marginal products,then the total share paid to labor could be total product less the cost of ranw materals. 5.(Samucison 17 sdition.p242 Chapter12-question?Draw the supply and demand curves for the oil market.Now suppose that a workable electrie car shifts demand away from oil.Draw the new demand curve and the new equilibrium.Describe the outcome in terms of the price of oil,the quantity consumed, and the tocal income of the oil producers Answers 5 (Samuekson,17 edition,p242.)Chapter12-question?.The price of oil will fall,as the quantity of ol produced and consumed will fall.The total income of ol producers will fall.Because there is a derived demand for gasoline,when the demand for gasoline-powered engines falls,the demand for gassoline will fall Price of gasoline Gasoline 6 (Samuelson 17 cdition p285 Chapterl4-question5,Using the supply and demand amlysis of interest,explain how each of the following woulld affect interest mtes in capital theory: a An innowation that increased the marginal product of capital at each level of capital. b.A decrease in the desired wealth holdings of households. c.A 50 percent tax on the return on capital (in the short run and the long run) Pf文件使用”pdfFactory Pro”试用版本创建.finsprint,cn

4 (b) If Ig decreases from $30 to $10, the new equilibrium GDP will be at GDP of $350, for with Ig now $10 this is where AE also equals $350. This indicates that the multiplier equals 5, for a decline in AE of $20 has led to a decline in equilibrium GDP of $100. The size of the multiplier could also have been calculated directly from the MPC of 0.8 . 4、Chapter12-question4. Why is each of the following incorrect? State the correct proposition. (Samuelson, 18th edition-chapter12, p242.) c) Marginal revenue product is calculated as total revenue earned per worker.(MRP is the additional revenue produced by an additional unit of input.) d) Distribution theory is simple. You simply figure out how much each factor produces and then give the factor its share of output. (Input contributions to production are interdependent, so it is impossible to determine what factor produced how much.) e) Under competition, workers get paid the total output produced minus the costs of raw materials. (If all factors are paid according to their marginal products, then the total share paid to labor could be total product less the cost of raw materials.) 5、(Samuelson, 17th edition, p242.) Chapter12-question7. Draw the supply and demand curves for the oil market.. Now suppose that a workable electric car shifts demand away from oil. Draw the new demand curve and the new equilibrium. Describe the outcome in terms of the price of oil, the quantity consumed, and the total income of the oil producers. Answers 5 (Samuelson, 17th edition, p242.) Chapter12-question7. The price of oil will fall, as the quantity of oil produced and consumed will fall. The total income of oil producers will fall. Because there is a derived demand for gasoline, when the demand for gasoline-powered engines falls, the demand for gasoline will fall. 6..(Samuelson, 17th edition, p285.) Chapter14-question5. Using the supply and demand analysis of interest, explain how each of the following would affect interest rates in capital theory: a. An innovation that increased the marginal product of capital at each level of capital. b. A decrease in the desired wealth holdings of households. c. A 50 percent tax on the return on capital (in the short run and the long run) E E' P P' q' q Gasoline Price of gasoline PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.cn

武汉大学经济与管理学院《西方经济学》试题(B卷) 2007年7月6日主讲：陈忠城审核姓名：学号：分数： 1、一个厂商的经济利润和会i计利润有什么不同？(What is a firm's cconomie profit and accounting profit?Are both the same?Explain.)(10) 2、宏观经济学中的价格和微观经济学中的价格有什么不同？(15分) 3、列出并解释总需求曲线向右下方领斜的三个原因。(15分) 4,汤母和古米两人开车到加油站，在看油价前，汤得说“我要10加仑汽油”，吉米说“我要10美元的汽油”。请计算两人各自的需求价格弹性？(15分) 5、假设某经济体的实际GDP第一年为3万美元，第二年为3.12万美元。求实际GDP的增长率？再假设第一年的人口为10D,第二年的人口为102.求人均GDP的增长半？(Suppose an economy's real GDP is $30.000 in year I and $31.200 in year 2.What is the growth rate of its real GDP?Assume that population was 100 in year I and 102 in year 2.What is the growth rate of GDP per capita7)(15分) 6.Assume the comsumption schedule for a private open economy is such that C=50+0.8y.Assume further that planned investment and net exports are independent of the level of income and constant at30 and10.Recall also that in equilibrium the real output produced (Y)is equal to the aggregate expenditures:YC+g(a)Cakculate the equilibrium level of income for this comy.(b)What will happen toequilibriumYifchanges to10 What does this tell you about the size of the multiplier？(l5分)】请从下列两题中任意透择一个图形分析题 ?、农业丰收了对农民来说是好消息还是坏消息？一场摧级了一半农作物的干早对农民是一件好事吗？如果这场干早对农民是好事，为什么农民不会在不干早时排毁白己的农作物？(Cn8 od news for farming be had news for farmers?How might a drought that destroys half of all farm crops be good for farmers?If such a drought is good for farmers,why don't farmers destroy their own crops in the absence of a drought?)(15分) 8.Larry.Curly,and Moe run the only saloon in town Larry wants to sell as many drinks as possible without losing money.Curly wants the saloon to bring in as much revenue as possible.Moe wants to 6 F文件使用"pdfFactory Pro”试用版本创建w,fineprint,cn

6 武汉大学经济与管理学院《西方经济学》试题(B 卷) 2007 年 7 月 6 日主讲：陈忠斌审核：姓名: 学号: 分数: 1、一个厂商的经济利润和会计利润有什么不同？（What is a firm’s economic profit and accounting profit? Are both the same? Explain.）（10 分） 2、宏观经济学中的价格和微观经济学中的价格有什么不同？（15 分） 3、列出并解释总需求曲线向右下方倾斜的三个原因。（15 分） 4、汤母和吉米两人开车到加油站，在看油价前，汤母说“我要 10 加仑汽油”，吉米说“我要 10 美元的汽油”。请计算两人各自的需求价格弹性？（15 分） 5、假设某一经济体的实际 GDP 第一年为 3 万美元，第二年为 3.12 万美元。求实际 GDP 的增长率？再假设第一年的人口为 100，第二年的人口为 102。求人均 GDP 的增长率？（Suppose an economy’s real GDP is $30,000 in year 1 and $31,200 in year 2. What is the growth rate of its real GDP? Assume that population was 100 in year 1 and 102 in year 2. What is the growth rate of GDP per capita?）（15 分） 6、Assume the consumption schedule for a private open economy is such that C = 50 + 0.8Y. Assume further that planned investment and net exports are independent of the level of income and constant at Ig = 30 and Xn = 10. Recall also that in equilibrium the real output produced (Y) is equal to the aggregate expenditures: Y = C + Ig + Xn . (a) Calculate the equilibrium level of income for this economy. (b)What will happen to equilibrium Y if Ig changes to 10? What does this tell you about the size of the multiplier? （15 分）请从下列两题中任意选择一个图形分析题 7、农业丰收了对农民来说是好消息还是坏消息？一场摧毁了一半农作物的干旱对农民是一件好事吗？如果这场干旱对农民是好事，为什么农民不会在不干旱时摧毁自己的农作物？（Can good news for farming be bad news for farmers? How might a drought that destroys half of all farm crops be good for farmers? If such a drought is good for farmers, why don’t farmers destroy their own crops in the absence of a drought?）（15 分） 8、Larry, Curly, and Moe run the only saloon in town. Larry wants to sell as many drinks as possible without losing money. Curly wants the saloon to bring in as much revenue as possible. Moe wants to PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.cn

武汉大学经济与管理学院《西方经济学》试题(B卷)参考答案 2007年7月6日主讲：陈忠斌 1.一个厂商的经济利间和会计利润有什么不同？(What is a firm's cconomie profit and accounting pof面？Are both the same?Explain)(10分) 答：。irm's economie profit=total revenue-explicit cost本-implicit costs a firm's accounting profit-total revenue-explicit costs. 2、宏观经济学中的价格和微观经济学中的价格有什么不同？(15分) 答：宏观经济学中的价格是某个经济体中整个商品和服务的物价总水平：微观经济学中的价格是指某一具体商品域服务市场的价格。如小麦的价格。籍肉的价格，理发的价格等。 3、列出并解释总需求曲线向右下方顿斜的三个原因。(15分) 答：(I)The Price Level and Consumption The Wealth Effect财富效应(Arthur Pigou.1877-l959列 A decrease in the price level makes comsumers feel more wealthy,which in turn encourages them to spend more.This increase in comsumer spending means larger quantities of goods and services demanded.(2) The Price Level and Investment:The Interest Rate Effect (John Maynard Keynes,1883-1946)-A lower price level reduces the interest rate,which encourages greater spending on investment goods.This increase in investment spending means a larger quantity of goods and services demanded (3)The Price Level and Net Exports:The Exchange-Rate Effect(Robert Mundell and Marcus Fleming)-When a fall in the U.S.price level causes U.S.interest rates to fall.the real exchange rate depreciates,which stimulates US net exports.The increase in net export spending means a larger quantity of goods and services demanded 4,汤母和吉米两人开车到加油站，在看油价前，汤得说“我要10加仑汽油”，喜米说“我要10美元的汽油”.请计算两人各自的需求价格弹性7《Twp-Tom and Jerry-each drive up to a gas station. Before looking at the price,each places an order.Tom says,"I'd like 10 gallons of gas"Jemry says,"I'd like $10 of gas."What is each driver's price elasticity of demand?) (15分) (a)Tom's price clasticity of demand is 0(or zero).He'd like 10 gallors of gas no matter the change in price of gas.that is change in quantity is zero. For Tom's price elasticity of demand is E= (ngiq)where q=0.So (nqiq-0. (Ap/p) (Ap/p) Se Tom's price elasticity of demand is 0. (b方法1 (Using mic-poimt approach,or arc-elasticity中 Jerry's price elasticity of demand is 1. 10 10 Jerry would like $10 of gas means that there exists always pg=10,thoar is =2= P PDF文件使用“pdfFactory Pro”试用版本创建，fineprint,cn

8 武汉大学经济与管理学院《西方经济学》试题(B 卷)参考答案 2007 年 7 月 6 日主讲：陈忠斌 1、一个厂商的经济利润和会计利润有什么不同？（What is a firm’s economic profit and accounting profit? Are both the same? Explain.）（10 分）答：a firm’s economic profit= total revenue - explicit costs - implicit costs a firm’s accounting profit=total revenue - explicit costs. 2、宏观经济学中的价格和微观经济学中的价格有什么不同？（15 分）答：宏观经济学中的价格是某个经济体中整个商品和服务的物价总水平；微观经济学中的价格是指某一具体商品或服务市场的价格，如小麦的价格，猪肉的价格，理发的价格等。 3、列出并解释总需求曲线向右下方倾斜的三个原因。（15 分）答：（1）The Price Level and Consumption: The Wealth Effect 财富效应 (Arthur Pigou, 1877-1959) A decrease in the price level makes consumers feel more wealthy, which in turn encourages them to spend more. This increase in consumer spending means larger quantities of goods and services demanded. （2） The Price Level and Investment: The Interest Rate Effect (John Maynard Keynes, 1883-1946)–A lower price level reduces the interest rate, which encourages greater spending on investment goods.This increase in investment spending means a larger quantity of goods and services demanded. （3）The Price Level and Net Exports: The Exchange-Rate Effect 汇率效应 (Robert Mundell and Marcus Fleming)–When a fall in the U.S. price level causes U.S. interest rates to fall, the real exchange rate depreciates, which stimulates U.S. net exports.The increase in net export spending means a larger quantity of goods and services demanded. 4、汤母和吉米两人开车到加油站，在看油价前，汤母说“我要 10 加仑汽油”，吉米说“我要 10 美元的汽油”。请计算两人各自的需求价格弹性？（Two--Tom and Jerry—each drive up to a gas station. Before looking at the price, each places an order. Tom says, “I’d like 10 gallons of gas.” Jerry says, “I’d like $10 of gas.” What is each driver’s price elasticity of demand?）（15 分）答：(a) Tom’s price elasticity of demand is 0 (or zero). He’d like 10 gallons of gas no matter the change in price of gas, that is change in quantity is zero. For Tom’s price elasticity of demand is ( ) ( p p) q q Ed Tom / / D D - = , where Dq = 0. So ( ) ( ) 0. / / = D D - = p p q q Ed Tom So Tom’s price elasticity of demand is 0. (b) 方法 1 (Using mid-point approach, or arc-elasticity)： Jerry’s price elasticity of demand is 1. Jerry would like $10 of gas means that there exists always . 10 10 10, 2 2 1 1 p q p pq = that is q = ， = PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.cn

9:-9: 10/P)-10/A) P-P: Ed-amy 9+93)/2 (9+9/2 101P)+10/P: P+P2 =-1 P:-P P一A P:-P (P+P/2 A+P/2 +P: P+P:) Se Jerry's price elastikcity of demand is 1. 方法2代ing point clasti试的pre电，运用点弹性方法： Jerry would like $10 of gas means that there exists always pg=10. 10 that is q=we ger 10 dp p E4-imy =7 P /可g产om-1 So Jerry's price elasticity of demand is 1. 5、假设某经济体的实际GDP第一年为3万美元，第二年为3.12万美元。求实际GDP的增长率？再假设第一年的人口为100，第二年的人口为102.求人均GDP的增长率？(Suppose an economy's real GDP is $30,000 in year I and $31,200 in year 2.What is the growth rate of its real GDP?Assume that population was 100 in year I and 102 in year 2.What is the growth rate of GDP per capit恤)(15分) Growth rate of real GDP =4 percent ($31,200-$30,000)$30,000).GDP per capita in year 1 -$300 (-$30,000V100).GDP per capita in year 2 $305.88 (=$31,200/102)Growth rate of GDP per capita is 1.96 percent =($305.88 -$300)300). 6 Assume the consumption schodule for a private open economy is such that C=50 0.87. Assume further that planned investment and net exports are independent of the level of income and constant at30 and=10.Recall also that in equilibrium the real output produced (Y)is equal to the aggregate expenditures:YC+ a Calculate the equilibrium level of income for this economy.Check your work by expressing the comsumption,investment,and net export schedules in tabular form and determining the equilibrium GDP b What will happen to equilibrium Y if le changes to 10?What does this tell you about the size of the multiplier? (a).y=C+1.+X.=s50+0.8y+330+s10=08y+s90 (a) 02y=390,→Y=450. the equilibrium level of income for this cconomy is $450. (b)If/decreases from $30 to $10,the new equilibrium GDP will be at GDP of $350.for with /g now $10 this is where AE also equals $350.This indicates that the multiplier equals'5.for a decline in AE of $20 has led to a decline in equilibrium GDP of $100. The size of the multiplier could also hve been cakulated directly from the MPC of 0.8 7.Can good news for farming be bad news for farmers?How might a drought that destroys half of all 9 PF文件使用"pdfFactory Pro”试用版本创建w.fineprint,n

9 1. (10 / ) (10 / ) (10 / ) (10 / ) ( ) / 2 ( ) / 2 ( ) / 2 ( ) / 2 1 2 2 1 1 2 1 2 1 2 2 1 1 2 2 1 1 2 2 1 1 2 2 1 1 2 1 2 = - ÷ ÷ ø ö ç ç è æ + - ÷ ÷ ø ö ç ç è æ + - = ÷ ÷ ø ö ç ç è æ + - ÷ ÷ ø ö ç ç è æ + - = ÷ ÷ ø ö ç ç è æ + - ÷ ÷ ø ö ç ç è æ + - = ÷ ÷ ø ö ç ç è æ + D ÷ ÷ ø ö ç ç è æ + D - = p p p p p p p p p p p p p p p p p p p p q q q q p p p q q q Ed Jerry So Jerry’s price elasticity of demand is 1. (b) 方法 2 (Using point elasticity approach, 运用点弹性方法)： Jerry would like $10 of gas means that there exists always pq =10. . 10 10 2 dp p dq we get p that is q = ， = - ( ) ( ) 1. (10 / ) 10 / / 2 = - ÷ ÷ ø ö ç ç è æ × ÷ ÷ ø ö ç ç è æ × = - D D = D D - = p p q p p p q p p q q Ed Jerry So Jerry’s price elasticity of demand is 1. 5、假设某一经济体的实际 GDP 第一年为 3 万美元，第二年为 3.12 万美元。求实际 GDP 的增长率？再假设第一年的人口为 100，第二年的人口为 102。求人均 GDP 的增长率？（Suppose an economy’s real GDP is $30,000 in year 1 and $31,200 in year 2. What is the growth rate of its real GDP? Assume that population was 100 in year 1 and 102 in year 2. What is the growth rate of GDP per capita?）（15 分）答：Growth rate of real GDP = 4 percent (= $31,200 - $30,000)/$30,000). GDP per capita in year 1 = $300 (= $30,000/100). GDP per capita in year 2 = $305.88 (= $31,200/102). Growth rate of GDP per capita is 1.96 percent = ($305.88 - $300)/300). 6 Assume the consumption schedule for a private open economy is such that C = 50 + 0.8Y. Assume further that planned investment and net exports are independent of the level of income and constant at Ig = 30 and Xn = 10. Recall also that in equilibrium the real output produced (Y) is equal to the aggregate expenditures: Y = C + Ig + Xn . a Calculate the equilibrium level of income for this economy. Check your work by expressing the consumption, investment, and net export schedules in tabular form and determining the equilibrium GDP. b What will happen to equilibrium Y if Ig changes to 10? What does this tell you about the size of the multiplier? (a) 0.2 $90, $450. ( ).. $50 0.8 $30 $10 0.8 $90, = Þ = = + + = + + + = + Y Y a Y C I g Xn Y Y the equilibrium level of income for this economy is $450. (b) If Ig decreases from $30 to $10, the new equilibrium GDP will be at GDP of $350, for with Ig now $10 this is where AE also equals $350. This indicates that the multiplier equals 5, for a decline in AE of $20 has led to a decline in equilibrium GDP of $100. The size of the multiplier could also have been calculated directly from the MPC of 0.8 . 7、Can good news for farming be bad news for farmers? How might a drought that destroys half of all PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.cn

10 farm crops be good for farmers? If such a drought is good for farmers, why don’t farmers destroy their own crops in the absence of a drought? // 农业丰收了对农民来说是好消息还是坏消息？一场摧毁了一半农作物的干旱对农民是一件好事吗？如果这场干旱对农民是好事，为什么农民不会在不干旱时摧毁自己的农作物？（15 分）答：（1）农业丰收了对农民来说是坏消息。因为农民作为一个整体的收入下降了，从图形中可以看出，农民原有的总收入是面积opE q1 ，农业丰收后农民的总收入是面积op¢E q¢ 2 。很明显，面积 op¢E q¢ 2 小于面积opE q1 ，这意味着农民整体的收入下降了。（2）一场摧毁了一半农作物的干旱对农民可能是一件好事。因为农民作为一个整体的收入上升了，从图形中可以看出，农民原有的总收入是面积 op¢E q¢ 2 ，农作物的干旱后农民的总收入是面积 opE q1 。很明显，面积opE q1 大于面积op¢E q¢ 2 ，这意味着农民整体的收入上升了。（3）农民不会在不干旱时摧毁自己的农作物。因为，在没有发生农作物干旱时，某个农民自己摧毁自己的农作物，并不能改变市场上农作物的价格，这只是意味着摧毁自己农作物的农民的收入会下降。 8、Larry, Curly, and Moe run the only saloon in town. Larry wants to sell as many drinks as possible without losing money. Curly wants the saloon to bring in as much revenue as possible. Moe wants to make the largest possible profits. Using a single diagram of the saloon’s demand curve and its cost curves, show the price and quantity combinations favored by each of the three partners. Explain. （15 分）答（见下页）： p p′ 0 S1 q q¢ Quantity Price S2 2. …leads to a large fall in price… 1. when demand is inelastic, an increase in supply… E2 E1 Demand 3. …and a proportionately smaller increase in quantity sold. As a result, revenue falls. PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.cn

武汉大学 试卷习题 西方经济学试题（A卷）及参考答案（2007.7.6）

武汉大学试卷习题西方经济学试题（A卷）及参考答案（2007.7.6）