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中级微观经济学范里安课后答案第1章市场说明：作为范里安《微观经济学：现代观点》教材的第一章，本章通过考察一个特定的市场模型——住房市场进行实例分析。
对于本章内容，建议学员简单了解即可。
钟根元《中级微观经济学学习指南》（第4版）未添加相关的练习题。
第2章预算约束一、判断题1考虑某消费者消费价格均为正的两种商品。
如果其中一种商品的价格下降了，而收入和另一种商品的价格保持不变，那么预算集范围缩小了。
（）【答案】F查看答案【解析】设消费者消费x和y两种商品，价格分别为px和py，收入为m。
设商品x的价格由px下降为px′，那么，如图2-1所示，预算线与横轴的交点由m/px右移至m/px′，预算线与纵轴的交点未变，显然，预算集的范围扩大了。
图2-1 价格下降引起的预算集变化2以横轴代表商品1，纵轴代表商品2，商品1价格为p1，商品2价格为p2，那么预算线的斜率为－p2/p1。
（）【答案】F查看答案【解析】如图2-2所示，预算线的斜率k＝－OA/OB，A为预算线与纵轴的交点，表示的是收入全部用于购买商品2时的消费量，即OA ＝m/p2，同理，OB＝m/p1，因此预算线的斜率为k＝－（m/p2）/（m/p1）＝－p1/p2。
图2-2 预算线3如果所有的商品价格都变为原来的两倍，而收入保持不变，那么预算集没有变化，因为相对价格没有变化。
（）【答案】F查看答案【解析】预算线方程为px＋py＝I，价格变为原来的两倍后，预算线变为2px＋2py＝I，或者px＋py＝I/2，显然，预算线斜率不变，但预算集范围缩小了。
4考虑两种商品，如果一种商品价格为正，而另一种商品价格为负（例如把“拾垃圾”也看成是“商品”，负的价格表示对消费者的补贴），那么预算线斜率为正。
（）【答案】T查看答案【解析】预算线的斜率为k＝－p1/p2，若一种商品价格为正，另一种商品价格为负，那么－p1/p2＞0，即预算线斜率为正。
5如果所有商品价格变为原来的两倍，收入变为原来的三倍，则预算线会更加陡峭。
目录一、简答题（3道） (2)1.期望效用与风险态度（需要计算和判断） (2)2.由显示偏好判断消费行为是否满足显示偏好弱公理（消费者是否理性） (8)3.举例说明正负外部性（消费或生产） (10)二、计算题（5选3，3必做，1和2选一个，4和5选一个） (13)1.禀赋收入效应、普通收入效应和替代效应 (13)2.消费者剩余的变化、补偿变换和等价变换 (18)3.税收和补贴对均衡的影响，税收或补贴的归宿 (21)4.古诺模型、卡特尔及囚徒困境博弈 (25)5.子博弈精炼纳什均衡 (27)三、分析题（2选1，一道大题一道小题） (30)差别定价（价格歧视） (30)两部收费制：案例分析题，企业如何运用两部收费制（垄断PPT43页） (36)一、简答题（3道）1.期望效用与风险态度（需要计算和判断）引入（1）期望效用的概念期望效用指的是消费者在不确定条件下可能获得的各种结果的效用的加权平均数，假设πa 表示结果a发生的概率，πna表示结果na发生的概率，c a表示结果a发生时的消费，c na表示结果na发生时的消费，则期望效用EU=πa U(c a)+πna U(c na)期望效用函数的特点①状态独立性（人们在一种自然状态下做出的选择，将独立于他们在另一种自然状态下做出的选择）②状态可加性③概率加权（因为效用与概率相关，赋予小概率事件更小的权重）*注意：期望效用仅仅是对个人偏好的一种假设，它是可以被推翻的（当人们考虑在两种东西中进行选择时，他们拥有的第三件东西的数量会影响其选择。
比如咖啡和茶的选择，在相当程度上取决于你拥有多少冰激凌）（2）根据效用函数判断风险态度①风险厌恶（更偏好财富的期望值而不是赌博本身）凹函数（凹向原点）u (12×15+12×5)=u (10)>12u (15)+12u (5)②风险偏好（更偏好的是财富的随机分布而不是财富的期望值） 凸函数（凸向原点）u (12×15+12×5)=u (10)<12u (15)+12u (5)效用函数是严格凸的，风险偏好 效用函数是严格凹的，风险厌恶 效用函数是一条直线，风险中性定理：一个投资者是（严格）风险厌恶的，其充要条件是他的确定性效用函数u( )是（严格）凹函数。
中级微观经济学1. 维克里拍卖定义：维克里拍卖的方式类似密封拍卖,但有一个重要区别：商品由报价最高的竞价人获得,但他只需要按第二高的报价支付。
换句话说，报价最高的投标人得到了拍卖商品,但是他不需要按照他自身的报价支付，而是按照报价第二高的人的报价支付。
特点：密封报、同时报价、价高者得、赢家支付次高价 分析:我们分析一个只有两个投标人的特殊情形。
这两人的对商品的评价分别为1v 和2v ,他们在纸条上写下的报价分别为1b 和2b 。
投标人1的期望收益为:如果21v ＞v ,最大化胜出的概率；也就是设置11v b =。
如果21v ＜v ，最小化胜出的概率；也就是设置11v b =. 任意情况,Telling the truth is best.2. 帕累托有效率如果可以找到一种配置，在其他人的境况没有变坏的情况下，的确能使一些人的境况变得更好一些，那么，这就叫做帕累托改进；如果一种配置方法存在帕累托改进,他就称为帕累托低效率；如果一种配置方法不存在任何的帕累托改进,他就称为帕累托有效率的。
3. 价格歧视，第一、二、三级价格歧视1.价格歧视:按不同价格销售不同单位产品的做法称为价格歧视2.一、二、三级价格歧视：第一级价格歧视:是指垄断企业按不同价格出售不同产量，而且这些价格可能因人而异。
这种价格歧视有时又称为完全价格歧视。
第二级价格歧视：是指,垄断企业按不同价格出售不同产量，但是购买相同数量的每个人支付价格是相同的。
因此,价格按购买数量制定,而不是因人而异.最常见的情形是大宗购买时可以享受折扣。
第三级价格歧视：是指垄断企业的销售价格因人而异,但对于同一个人来说，每单位产品的售价是相同的。
这种价格歧视最常见.例如：对老年人打折，对学生打折等。
4.消费者剩余消费者剩余：是指购买者的支付意愿减去购买者的实际支付量。
消费者剩余衡量了购买者自己感觉到所获得的额外收益.5.显示偏好原理1.显示偏好：假定：（1)所有消费者的偏好都是严格凸性的，因此对于一个预算线来说都有且只有一个最优消费束。
中级微观经济学-范里安版本xx年xx月xx日contents •消费者理论•生产者理论•市场理论•福利经济学•微观经济政策•中级微观经济学的前沿进展目录01消费者理论消费者对不同商品或商品组合的喜好程度，用于排序各种商品或商品组合的效用水平。
偏好消费者从消费某种商品或商品组合中获得的满足程度，取决于消费者的偏好。
效用偏好与效用优化选择与需求优化选择在给定预算约束和各种商品价格的情况下，消费者会选择最大化自己效用的商品组合。
需求消费者在特定价格下愿意购买的商品数量，取决于消费者的偏好和价格。
消费者剩余消费者购买商品时愿意支付的价格与实际支付价格之间的差额，取决于消费者的偏好和价格。
需求弹性消费者对价格变动的反应程度，即需求量变动百分比与价格变动百分比的比率，分为需求收入弹性和需求价格弹性。
消费者剩余与需求弹性02生产者理论介绍生产函数和要素投入之间的关系，包括线性生产函数和非线性生产函数。
根据利润函数，推导厂商最优产量和最优要素投入量的选择，以及在完全竞争和垄断市场中的利润情况。
生产技术利润最大化生产技术与利润成本最小化根据成本函数，推导厂商最优要素投入量和产出量的选择，以及在完全竞争和垄断市场中的成本情况。
产出最大化根据收益函数，推导厂商最优产出量的选择，以及在完全竞争和垄断市场中的收益情况。
成本最小化与产出最大化完全竞争市场中的厂商行为完全竞争市场介绍完全竞争市场的特点和基本假设，包括同质产品、自由进入和退出等。
厂商行为根据市场需求和供给，推导厂商最优产量和价格的选择，以及在完全竞争市场中的市场份额和利润情况。
03市场理论完全竞争市场的价格与产总结词：价格接受者详细描述：在完全竞争市场中，每个厂商都是价格接受者，即他们只能被动接受市场决定的价格，因此，每个厂商的边际收益等于市场价格。
总结词：市场出清详细描述：由于每个厂商都是价格接受者，因此，他们将生产直至边际收益等于零，即市场将出清。
总结词：平均成本与利润详细描述：在完全竞争市场中，每个厂商的平均收益等于平均成本，因此，他们只能获得正常利润。
范里安中级微观经济学题库在范里安中级微观经济学题库中，涵盖了微观经济学的多个重要主题，包括供给与需求、消费者行为、生产者行为、市场结构等等。
通过学习和解答这些题目，可以加深对微观经济学理论的理解，并提高解决经济问题的能力。
下面是一些范里安中级微观经济学题库中的样例题目及其解答，供大家参考。
1. 供给与需求题目：某种商品的市场需求曲线为Qd = 1000 - 2P，市场供给曲线为Qs = 500 + 3P。
求市场平衡时的价格和数量。
解答：市场平衡时，供给量等于需求量，即Qs = Qd。
代入供给和需求的曲线方程，得到500 + 3P = 1000 - 2P。
整理方程，得到5P = 500，解得P = 100。
将P = 100代入需求曲线，得到Qd = 1000 - 2×100 = 800。
所以市场平衡时的价格为100，数量为800。
2. 消费者行为题目：某消费者的收入为500元，某商品的价格为5元，该消费者对该商品的需求量与价格之间的关系如下：Qd = 10 - 2P。
求该消费者对该商品的需求函数，并判断该商品是否为正常商品或劣质商品。
解答：需求函数表示需求量与价格之间的关系，根据题目中的信息可得到需求函数为Qd = 10 - 2P。
当收入增加时，需求量随之增加，所以该商品为正常商品。
3. 生产者行为题目：某企业的生产函数为Q = L^0.5K^0.5，其中Q为产量，L为劳动力投入，K为资本投入。
该企业的生产函数是否具有规模报酬递减性？请给出理由。
解答：生产函数具有规模报酬递减性意味着当生产要素投入增加时，边际产量递减。
我们可以对生产函数进行计算，得到边际产量函数。
边际产量函数为dQ/dL = 0.5L^(-0.5)K^0.5。
可以看出，当L增加时，边际产量递减；当K增加时，边际产量也递减。
因此，该企业的生产函数具有规模报酬递减性。
4. 市场结构题目：某市场上有4家企业，市场需求曲线为Qd = 1000 - 2P，每家企业的成本函数为TC = 100Q + 1000。
第一部分 消费者选择理论1.有两种商品，x1和x2，价格分别为p1和p2，收入为m 。
当11x x ≥时，政府加数量税t,画出预算集并写出预算线2. 消费者消费两种商品（x1，x2），如果花同样多的钱可以买（4，6）或（12，2），写出预算线的表达式。
3．重新描述中国粮价改革（1）假设没有任何市场干预，中国的粮价为每斤0。
4元，每人收入为100元。
把粮食消费量计为x ，在其它商品上的开支为y ，写出预算线，并画图。
（2）假设每人得到30斤粮票，可以凭票以0。
2元的价格买粮食，再写预算约束，画图。
（3）假设取消粮票，补贴每人6元钱，写预算约束并画图。
4． 证两条无差异曲线不能相交5． 一元纸币（x1）和五元纸币（x2）的边际替代率是多少？ 6． 若商品1为中性商品，则它对商品2的边际替代率？7. 写出下列情形的效用函数，画出无差异曲线，并在给定价格（p 1，p 2）和收入（m ）的情形下求最优解。
（1）x 1=一元纸币，x 2=五元纸币。
（2）x 1=一杯咖啡，x 2=一勺糖, 消费者喜欢在每杯咖啡加两勺糖。
8. 解最优选择 （1）21212(,)u x x x x =⋅（2）2u x =+9. 对下列效用函数推导对商品1的需求函数，反需求函数，恩格尔曲线；在图上大致画出价格提供曲线，收入提供曲线；说明商品一是否正常品、劣质品、一般商品、吉芬商品，商品二与商品一是替代还是互补关系。
（1）212x x u += （2）()212,m in x x u =（3）ba x x u 21⋅=（4） 12ln u x x =+,10. 当偏好为完全替代时，计算当价格变化时的收入效用和替代效用（注意分情况讨论）。
11. 给定效用函数 (,)x y xy =，p x =3，p y =4，m=60，求当p y 降为3时价格变化引起的替代效应和收入效应。
12. 用显示偏好的弱公理说明为什么Slutsky 替代效应为负。
Chapter1NAMEThe MarketIntroduction.The problems in this chapter examine some variations on the apartment market described in the text.In most of the problems we work with the true demand curve constructed from the reservation prices of the consumers rather than the“smoothed”demand curve that we used in the text.Remember that the reservation price of a consumer is that price where he is just indifferent between renting or not renting the apartment. At anyprice below the reservation price the consumer will demand one apartment,at anyprice above the reservation price the consumer will de-mand zero apartments,and exactlyat the reservation price the consumer will be indifferent between having zero or one apartment.You should also observe that when demand curves have the“stair-case”shape used here,there will typically be a range of prices where supplyequals demand.Thus we will ask for the the highest and lowest price in the range.1.1(3)Suppose that we have8people who want to rent an apartment. Their reservation prices are given below.(To keep the numbers small, think of these numbers as being dailyrent pay ments.)Person=A B C D E F G HPrice=402530351018155(a)Plot the market demand curve in the following graph.(Hint:When the market price is equal to some consumer i’s reservation price,there will be two different quantities of apartments demanded,since consumer i will be indifferent between having or not having an apartment.)2THE MARKET(Ch.1)012345678102030406050PriceApartments(b)Suppose the supplyof apartments isfixed at5units.In this case there is a whole range of prices that will be equilibrium prices.What is the highest price that would make the demand for apartments equal to5 units?$18.(c)What is the lowest price that would make the market demand equal to5units?$15.(d)With a supplyof4apartments,which of the people A–H end up getting apartments?A,B,C,D.(e)What if the supplyof apartments increases to6units.What is the range of equilibrium prices?$10to$15.1.2(3)Suppose that there are originally5units in the market and that 1of them is turned into a condominium.(a)Suppose that person A decides to buythe condominium.What will be the highest price at which the demand for apartments will equal the supplyof apartments?What will be the lowest price?Enter y our an-swers in column A,in the table.Then calculate the equilibrium prices of apartments if B,C,...,decide to buythe condominium.NAME3Person A B C D E F G H High price1818181825252525 Low price1515151518151818 (b)Suppose that there were two people at each reservation price and10 apartments.What is the highest price at which demand equals supply?18.Suppose that one of the apartments was turned into a condo-minium.Is that price still an equilibrium price?Yes.1.3(2)Suppose now that a monopolist owns all the apartments and thathe is trying to determine which price and quantity maximize his revenues.(a)Fill in the box with the maximum price and revenue that the monop-olist can make if he rents1,2,...,8apartments.(Assume that he must charge one price for all apartments.)Number12345678 Price403530251815105 Revenue40709010090907040(b)Which of the people A–F would get apartments?A,B,C,D.(c)If the monopolist were required bylaw to rent exactly5apartments, what price would he charge to maximize his revenue?$18.(d)Who would get apartments?A,B,C,D,F.(e)If this landlord could charge each individual a different price,and heknew the reservation prices of all the individuals,what is the maximum revenue he could make if he rented all5apartments?$148.(f)If5apartments were rented,which individuals would get the apart-ments?A,B,C,D,F.1.4(2)Suppose that there are5apartments to be rented and that the cityrent-control board sets a maximum rent of$9.Further suppose that people A,B,C,D,and E manage to get an apartment,while F,G,andH are frozen out.4THE MARKET(Ch.1)(a)If subletting is legal—or,at least,practiced—who will sublet to whomin equilibrium?(Assume that people who sublet can evade the cityrent-control restrictions.)E,who is willing to payonly$10for an apartment would sublet to F,who is willing to pay$18.(b)What will be the maximum amount that can be charged for the sublet payment?$18.(c)If you have rent control with unlimited subletting allowed,which ofthe consumers described above will end up in the5apartments?A,B,C,D,F.(d)How does this compare to the market outcome?It’s the same.1.5(2)In the text we argued that a tax on landlords would not getpassed along to the renters.What would happen if instead the tax wasimposed on renters?(a)To answer this question,consider the group of people in Problem1.1.What is the maximum that theywould be willing to payto the landlordif theyeach had to paya$5tax on apartments to the city?Fill in thebox below with these reservation prices.Person A B C D E F G H Reservation Price35202530513100 (b)Using this information determine the maximum equilibrium price ifthere are5apartments to be rented.$13.(c)Of course,the total price a renter pays consists of his or her rent plusthe tax.This amount is$18.(d)How does this compare to what happens if the tax is levied on the landlords?It’s the same.Chapter 2NAMEBudget ConstraintIntroduction.These workouts are designed to build your skills in de-scribing economic situations with graphs and algebra.Budget sets are a good place to start,because both the algebra and the graphing are very easy.Where there are just two goods,a consumer who consumes x 1units of good 1and x 2units of good 2is said to consume the consumption bun-dle ,(x 1,x 2).Anyconsumption bundle can be represented bya point on a two-dimensional graph with quantities of good 1on the horizontal axis and quantities of good 2on the vertical axis.If the prices are p 1for good 1and p 2for good 2,and if the consumer has income m ,then she can afford anyconsumption bundle,(x 1,x 2),such that p 1x 1+p 2x 2≤m .On a graph,the budget line is just the line segment with equation p 1x 1+p 2x 2=m and with x 1and x 2both nonnegative.The budget line is the boundary of the budget set .All of the points that the consumer can afford lie on one side of the line and all of the points that the consumer cannot afford lie on the other.If you know prices and income,you can construct a consumer’s bud-get line byfinding two commoditybundles that she can “just afford”and drawing the straight line that runs through both points.Example:Myrtle has 50dollars to spend.She consumes only apples and bananas.Apples cost 2dollars each and bananas cost 1dollar each.You are to graph her budget line,where apples are measured on the horizontal axis and bananas on the vertical axis.Notice that if she spends all of her income on apples,she can afford 25apples and no bananas.Therefore her budget line goes through the point (25,0)on the horizontal axis.If she spends all of her income on bananas,she can afford 50bananas and no apples.Therfore her budget line also passes throught the point (0,50)on the vertical axis.Mark these two points on your graph.Then draw a straight line between them.This is Myrtle’s budget line.What if you are not told prices or income,but you know two com-moditybundles that the consumer can just afford?Then,if there are just two commodities,you know that a unique line can be drawn through two points,so you have enough information to draw the budget line.Example:Laurel consumes onlyale and bread.If she spends all of her income,she can just afford 20bottles of ale and 5loaves of bread.Another commoditybundle that she can afford if she spends her entire income is 10bottles of ale and 10loaves of bread.If the price of ale is 1dollar per bottle,how much moneydoes she have to spend?You could solve this problem graphically.Measure ale on the horizontal axis and bread on the vertical axis.Plot the two points,(20,5)and (10,10),that you know to be on the budget line.Draw the straight line between these points and extend the line to the horizontal axis.This point denotes the amount of6BUDGET CONSTRAINT (Ch.2)ale Laurel can afford if she spends all of her moneyon ale.Since ale costs 1dollar a bottle,her income in dollars is equal to the largest number of bottles she can afford.Alternatively,you can reason as follows.Since the bundles (20,5)and (10,10)cost the same,it must be that giving up 10bottles of ale makes her able to afford an extra 5loaves of bread.So bread costs twice as much as ale.The price of ale is 1dollar,so the price of bread is 2dollars.The bundle (20,5)costs as much as her income.Therefore her income must be 20×1+5×2=30.When you have completed this workout,we hope that you will be able to do the following:•Write an equation for the budget line and draw the budget set on a graph when you are given prices and income or when you are given two points on the budget line.•Graph the effects of changes in prices and income on budget sets.•Understand the concept of numeraire and know what happens to the budget set when income and all prices are multiplied bythe same positive amount.•Know what the budget set looks like if one or more of the prices is negative.•See that the idea of a “budget set”can be applied to constrained choices where there are other constraints on what you can have,in addition to a constraint on moneyexpenditure.NAME 72.1(0)You have an income of $40to spend on two -modity1costs $10per unit,and commodity2costs $5per unit.(a)Write down your budget equation.10x 1+5x 2=40.(b)If you spent all your income on commodity 1,how much could you buy?4.(c)If you spent all of your income on commodity 2,how much could you buy?8.Use blue ink to draw your budget line in the graphbelow.02468246x1x28(d)Suppose that the price of commodity1falls to $5while every thing else stays the same.Write down your new budget equation.5x 1+5x 2=40.On the graph above,use red ink to draw your new budget line.(e)Suppose that the amount you are allowed to spend falls to $30,while the prices of both commodities remain at $5.Write down your budget equation.5x 1+5x 2=30.Use black ink to draw this budget line.(f)On your diagram,use blue ink to shade in the area representing com-moditybundles that y ou can afford with the budget in Part (e)but could not afford to buywith the budget in Part (a).Use black ink or pencil to shade in the area representing commoditybundles that y ou could afford with the budget in Part (a)but cannot afford with the budget in Part (e).2.2(0)On the graph below,draw a budget line for each case.8BUDGET CONSTRAINT (Ch.2)(a)p 1=1,p 2=1,m =15.(Use blue ink.)(b)p 1=1,p 2=2,m =20.(Use red ink.)(c)p 1=0,p 2=1,m =10.(Use black ink.)(d)p 1=p 2,m =15p 1.(Use pencil or black ink.Hint:How much of good 1couldyou afford if you spend your entire budget on good 1?)0510152051015x1x2202.3(0)Your budget is such that if you spend your entire income,youcan afford either 4units of good x and 6units of good y or 12units of x and 2units of y .(a)Mark these two consumption bundles and draw the budget line in the graph below.04812164812xy 16(b)What is the ratio of the price of x to the price of y ?1/2.(c)If you spent all of your income on x ,how much x could you buy?16.(d)If you spent all of your income on y ,how much y could you buy?8.(e)Write a budget equation that gives you this budget line,where the price of x is 1.x +2y =16.(f)Write another budget equation that gives you the same budget line,but where the price of x is 3.3x +6y =48.2.4(1)Murphywas consuming 100units of X and 50units of Y .Theprice of X rose from 2to 3.The price of Y remained at 4.(a)How much would Murphy’s income have to rise so that he can still exactlyafford 100units of X and 50units of Y ?$100.2.5(1)If Amyspent her entire allowance,she could afford 8candybars and 8comic books a week.She could also just afford 10candybars and 4comic books a week.The price of a candybar is 50cents.Draw her budget line in the box below.What is Amy’s weekly allowance?$6.0816243281624Candy barsComic books3212 2.6(0)In a small countrynear the Baltic Sea,there are onlythree commodities:potatoes,meatballs,and jam.Prices have been remark-ablystable for the last 50y ears or so.Potatoes cost 2crowns per sack,meatballs cost 4crowns per crock,and jam costs 6crowns per jar.(a)Write down a budget equation for a citizen named Gunnar who has an income of 360crowns per year.Let P stand for the number of sacks of potatoes,M for the number of crocks of meatballs,and J for the number of jars of jam consumed byGunnar in a y ear.2P +4M +6J =360.(b)The citizens of this countryare in general veryclever people,but they are not good at multiplying by 2.This made shopping for potatoes excru-ciatinglydifficult for manycitizens.Therefore it was decided to introduce a new unit of currency,such that potatoes would be the numeraire.A sack of potatoes costs one unit of the new currencywhile the same rel-ative prices applyas in the past.In terms of the new currency ,what is the price of meatballs?2crowns.(c)In terms of the new currency,what is the price of jam?3crowns.(d)What would Gunnar’s income in the new currencyhave to be for him to be exactlyable to afford the same commoditybundles that he could afford before the change?180crowns.(e)Write down Gunnar’s new budget equation.P +2M +3J =180.Is Gunnar’s budget set anydifferent than it was before the change?No.2.7(0)Edmund Stench consumes two commodities,namelygarbage and punk rock video cassettes.He doesn’t actuallyeat the former but keeps it in his backy ard where it is eaten bybillygoats and assorted vermin.The reason that he accepts the garbage is that people payhim $2per sack for taking it.Edmund can accept as much garbage as he wishes at that price.He has no other source of income.Video cassettes cost him $6each.(a)If Edmund accepts zero sacks of garbage,how manyvideo cassettescan he buy?0.NAME 11(b)If he accepts 15sacks of garbage,how manyvideo cassettes can he buy?5.(c)Write down an equation for his budget line.6C −2G =0.(d)Draw Edmund’s budget line and shade in his budget set.0510152051015Video cassettesGarbage 202.8(0)If you think Edmund is odd,consider his brother Emmett.Emmett consumes speeches bypoliticians and universityadministrators.He is paid $1per hour for listening to politicians and $2per hour for listening to universityadministrators.(Emmett is in great demand to help fill emptychairs at public lectures because of his distinguished appearance and his abilityto refrain from making rude noises.)Emmett consumes one good for which he must pay.We have agreed not to disclose what that good is,but we can tell you that it costs $15per unit and we shall call it Good X .In additionto what he is paid for consuming speeches,Emmett receives a pension of $50per week.0255075100255075Politician speechesAdministrator speeches10012BUDGET CONSTRAINT (Ch.2)(a)Write down a budget equation stating those combinations of the three commodities,Good X ,hours of speeches bypoliticians (P ),and hours of speeches byuniversityadministrators (A )that Emmett could afford to consume per week.15X −1P −2A =50.(b)On the graph above,draw a two-dimensional diagram showing the locus of consumptions of the two kinds of speeches that would be possible for Emmett if he consumed 10units of Good X per week.2.9(0)Jonathan Livingstone Yuppie is a prosperous lawyer.He has,in his own words,“outgrown those confining two-commoditylim-its.”Jonathan consumes three goods,unblended Scotch whiskey,de-signer tennis shoes,and meals in French gourmet restaurants.The price of Jonathan’s brand of whiskeyis $20per bottle,the price of designer tennis shoes is $80per pair,and the price of gourmet restaurant meals is $50per meal.After he has paid his taxes and alimony,Jonathan has $400a week to spend.(a)Write down a budget equation for Jonathan,where W stands for the number of bottles of whiskey,T stands for the number of pairs of tennis shoes,and M for the number of gourmet restaurant meals that he consumes.20W +80T +50M =400.(b)Draw a three-dimensional diagram to show his budget bel the intersections of the budget set with each axis.(c)Suppose that he determines that he will buyone pair of designer tennis shoes per week.What equation must be satisfied bythe combinations of restaurant meals and whiskeythat he could afford?20W +50M =320.2.10(0)Martha is preparing for exams in economics and sociology.She has time to read 40pages of economics and 30pages of sociology.In the same amount of time she could also read 30pages of economics and 60pages of sociology.(a)Assuming that the number of pages per hour that she can read of either subject does not depend on how she allocates her time,how many pages of sociologycould she read if she decided to spend all of her time on sociologyand none on economics?150pages.(Hint:You have two points on her budget line,so you should be able to determine the entire line.)(b)How manypages of economics could she read if she decided to spend all of her time reading economics?50pages.2.11(1)HarryHy pe has $5,000to spend on advertising a new kind ofdehydrated sushi.Market research shows that the people most likely to buythis new product are recent recipients of M.B.A.degrees and lawy ers who own hot tubs.Harryis considering advertising in two publications,a boring business magazine and a trendyconsumer publication for people who wish theylived in California.Fact 1:Ads in the boring business magazine cost $500each and ads in the consumer magazine cost $250each.Fact 2:Each ad in the business magazine will be read by1,000recent M.B.A.’s and 300lawyers with hot tubs.Fact 3:Each ad in the consumer publication will be read by300recent M.B.A.’s and 250lawyers who own hot tubs.Fact 4:Nobodyreads more than one ad,and nobodywho reads one magazine reads the other.(a)If Harryspends his entire advertising budget on the business pub-lication,his ad will be read by10,000recent M.B.A.’s and by3,000lawyers with hot tubs.(b)If he spends his entire advertising budget on the consumer publication,his ad will be read by 6,000recent M.B.A.’s and by5,000lawyers with hot tubs.(c)Suppose he spent half of his advertising budget on each publication.His ad would be read by 8,000recent M.B.A.’s and by4,000lawyers with hot tubs.(d)Draw a “budget line”showing the combinations of number of readings byrecent M.B.A.’s and bylawy ers with hot tubs that he can obtain if he spends his entire advertising budget.Does this line extend all the way to the axes?No.Sketch,shade in,and label the budget set,which includes all the combinations of MBA’s and lawyers he can reach if he spends no more than his budget.(e)Let M stand for the number of instances of an ad being read byan M.B.A.and L stand for the number of instances of an ad being read by a lawyer.This budget line is a line segment that lies on the line with equation M +2L =16.With a fixed advertising budget,how manyreadings byM.B.A.’s must he sacrifice to get an additional reading bya lawy er with a hot tub?2.04812164812Lawyers x 1000MBA's x 10001610262.12(0)On the planet Mungo,theyhave two kinds of money ,blue moneyand red money .Everycommodityhas two prices—a red-money price and a blue-moneyprice.EveryMungoan has two incomes—a red income and a blue income.In order to buyan object,a Mungoan has to paythat object’s red-moneyprice in red moneyand its blue-moneyprice in blue money .(The shops simplyhave two cash registers,and y ou have to payat both registers to buyan object.)It is forbidden to trade one kind of moneyfor the other,and this prohibition is strictlyenforced byMungo’s ruthless and efficient monetarypolice.•There are just two consumer goods on Mungo,ambrosia and bubble gum.All Mungoans prefer more of each good to less.•The blue prices are 1bcu (bcu stands for blue currencyunit)per unit of ambrosia and 1bcu per unit of bubble gum.•The red prices are 2rcus (red currencyunits)per unit of ambrosia and 6rcus per unit of bubble gum.(a)On the graph below,draw the red budget (with red ink)and the blue budget (with blue ink)for a Mungoan named Harold whose blue income is 10and whose red income is 30.Shade in the “budget set”containing all of the commoditybundles that Harold can afford,givenNAME 15its ∗two budget constraints.Remember,Harold has to have enough blue money and enough red moneyto payboth the blue-moneycost and the red-moneycost of a bundle ofgoods.0510152051015AmbrosiaGum 20(b)Another Mungoan,Gladys,faces the same prices that Harold faces and has the same red income as Harold,but Gladys has a blue income of 20.Explain how it is that Gladys will not spend its entire blue income no matter what its tastes maybe.(Hint Draw Glady s’s budget lines.)The blue budget line lies strictlyoutside the red budget line,so to satisfyboth budgets,one must be strictlyinside the red budget line.(c)A group of radical economic reformers on Mungo believe that the currencyrules are unfair.“Whyshould every one have to paytwo prices for every thing?”theyask.Theypropose the following scheme.Mungo will continue to have two currencies,everygood will have a blue price and a red price,and everyMungoan will have a blue income and a red income.But nobodyhas to payboth prices.Instead,every one on Mungo must declare itself to be either a Blue-MoneyPurchaser (a “Blue”)or a Red-Money Purchaser (a “Red”)before it buys anything at all.Blues must make all of their purchases in blue moneyat the blue prices,spending onlytheir blue incomes.Reds must make all of their purchases in red money,spending only their red incomes.Suppose that Harold has the same income after this reform,and that prices do not change.Before declaring which kind of purchaser it will be,∗We refer to all Mungoans bythe gender-neutral pronoun,“it.”Al-though Mungo has two sexes,neither of them is remotelylike either of ours.16BUDGET CONSTRAINT (Ch.2)Harold contemplates the set of commoditybundles that it could afford bymaking one declaration or the other.Let us call a commoditybundle “attainable”if Harold can afford it bydeclaring itself to be a “Blue”and buying the bundle with blue money or if Harold can afford the bundle bydeclaring itself to be a “Red”and buy ing it with red money .On the diagram below,shade in all of the attainable bundles.0510152051015AmbrosiaGum202.13(0)Are Mungoan budgets reallyso fanciful?Can y ou think of sit-uations on earth where people must simultaneouslysatisfymore than onebudget constraint?Is moneythe onlyscarce resource that people use up when consuming?Consumption of manycommoditiestakes time as well as money.People have to simultaneouslysatisfya time budget and a moneybudget.Other examples--people mayhave a calorie budget or a cholesterol budget or an alcohol-intake budget.Chapter 3NAMEPreferencesIntroduction.In the previous section you learned how to use graphs toshow the set of commoditybundles that a consumer can afford.In this section,you learn to put information about the consumer’s preferences on the same kind of graph.Most of the problems ask you to draw indifference curves.Sometimes we give you a formula for the indifference curve.Then all you have to do is graph a known equation.But in some problems,we give you only “qualitative”information about the consumer’s preferences and ask you to sketch indifference curves that are consistent with this information.This requires a little more thought.Don’t be surprised or disappointed if you cannot immediately see the answer when you look at a problem,and don’t expect that you will find the answers hiding somewhere in your textbook.The best way we know to find answers is to “think and doodle.”Draw some axes on scratch paper and label them,then mark a point on your graph and ask yourself,“What other points on the graph would the consumer find indifferent to this point?”If possible,draw a curve connecting such points,making sure that the shape of the line you draw reflects the features required by the problem.This gives you one indifference curve.Now pick another point that is preferred to the first one you drew and draw an indifference curve through it.Example:Jocasta loves to dance and hates housecleaning.She has strictly convex preferences.She prefers dancing to anyother activityand never gets tired of dancing,but the more time she spends cleaning house,the less happyshe is.Let us tryto draw an indifference curve that is consistent with her preferences.There is not enough information here to tell us exactlywhere her indifference curves go,but there is enough information to determine some things about their shape.Take a piece of scratch paper and draw a pair of bel the horizontal axis “Hours per dayof housecleaning.”Label the vertical axis “Hours per dayof dancing.”Mark a point a little ways up the vertical axis and write a 4next to it.At this point,she spends 4hours a daydancing and no time housecleaning.Other points that would be indifferent to this point would have to be points where she did more dancing and more housecleaning.The pain of the extra housekeeping should just compensate for the pleasure of the extra dancing.So an indifference curve for Jocasta must be upward sloping.Because she loves dancing and hates housecleaning,it must be that she prefers all the points above this indifference curve to all of the points on or below it.If Jocasta has strictlyconvex preferences,then it must be that if you draw a line between any two points on the same indifference curve,all the points on the line (except the endpoints)are preferred to the endpoints.For this to be the case,it must be that the indifference curve slopes upward ever more steeplyas y ou move to the right along it.You should convince yourself of this by making some drawings on scratch18PREFERENCES (Ch.3)paper.Draw an upward-sloping curve passing through the point (0,4)and getting steeper as one moves to the right.When you have completed this workout,we hope that you will be able to do the following:•Given the formula for an indifference curve,draw this curve,and find its slope at anypoint on the curve.•Determine whether a consumer prefers one bundle to another or is indifferent between them,given specific indifference curves.•Draw indifference curves for the special cases of perfect substitutes and perfect complements.•Draw indifference curves for someone who dislikes one or both com-modities.•Draw indifference curves for someone who likes goods up to a point but who can get “too much”of one or more goods.•Identifyweaklypreferred sets and determine whether these are con-vex sets and whether preferences are convex.•Know what the marginal rate of substitution is and be able to deter-mine whether an indifference curve exhibits “diminishing marginal rate of substitution.”•Determine whether a preference relation or anyother relation be-tween pairs of things is transitive,whether it is reflexive,and whether it is complete.3.1(0)Charlie likes both apples and bananas.He consumes nothing else.The consumption bundle where Charlie consumes x A bushels of apples per year and x B bushels of bananas per year is written as (x A ,x B ).Last year,Charlie consumed 20bushels of apples and 5bushels of bananas.It happens that the set of consumption bundles (x A ,x B )such that Charlie is indifferent between (x A ,x B )and (20,5)is the set of all bundles such that x B =100/x A .The set of bundles (x A ,x B )such that Charlie is just indifferent between (x A ,x B )and the bundle (10,15)is the set of bundles such that x B =150/x A .(a)On the graph below,plot several points that lie on the indifference curve that passes through the point (20,5),and sketch this curve,using blue ink.Do the same,using red ink,for the indifference curve passing through the point (10,15).(b)Use pencil to shade in the set of commoditybundles that Charlie weaklyprefers to the bundle (10,15).Use blue ink to shade in the set of commoditybundles such that Charlie weaklyprefers (20,5)to these bundles.NAME 19010203040102030ApplesBananas 40For each of the following statements about Charlie’s preferences,write “true”or “false.”(c)(30,5)∼(10,15).True.(d)(10,15) (20,5).True.(e)(20,5) (10,10).True.(f)(24,4) (11,9.1).False.(g)(11,14) (2,49).True.(h)A set is convex if for anytwo points in the set,the line segment between them is also in the set.Is the set of bundles that Charlie weakly prefers to (20,5)a convex set?Yes.(i)Is the set of bundles that Charlie considers inferior to (20,5)a convex set?No.(j)The slope of Charlie’s indifference curve through a point,(x A ,x B ),is known as his marginalrateofsubstitutionat that point.20PREFERENCES (Ch.3)(k)Remember that Charlie’s indifference curve through the point (10,10)has the equation x B =100/x A .Those of you who know calculus will remember that the slope of a curve is just its derivative,which in this case is −100/x 2A .(If you don’t know calculus,you will have to take our word for this.)Find Charlie’s marginal rate of substitution at the point,(10,10).−1.(l)What is his marginal rate of substitution at the point (5,20)?−4.(m)What is his marginal rate of substitution at the point (20,5)?(−.25).(n)Do the indifference curves you have drawn for Charlie exhibit dimin-ishing marginal rate of substitution?Yes.3.2(0)Ambrose consumes onlynuts and berries.Fortunately ,he likes both goods.The consumption bundle where Ambrose consumes x 1units of nuts per week and x 2units of berries per week is written as (x 1,x 2).The set of consumption bundles (x 1,x 2)such that Ambrose is indifferent between (x 1,x 2)and (1,16)is the set of bundles such that x 1≥0,x 2≥0,and x 2=20−4√x 1.The set of bundles (x 1,x 2)such that (x 1,x 2)∼(36,0)is the set of bundles such that x 1≥0,x 2≥0and x 2=24−4√x 1.(a)On the graph below,plot several points that lie on the indifference curve that passes through the point (1,16),and sketch this curve,using blue ink.Do the same,using red ink,for the indifference curve passing through the point (36,0).(b)Use pencil to shade in the set of commoditybundles that Ambrose weaklyprefers to the bundle (1,16).Use red ink to shade in the set of all commoditybundles (x 1,x 2)such that Ambrose weaklyprefers (36,0)to these bundles.Is the set of bundles that Ambrose prefers to (1,16)a convex set?Yes.(c)What is the slope of Ambrose’s indifference curve at the point (9,8)?(Hint Recall from calculus the wayto calculate the slope of a curve.If you don’t know calculus,you will have to draw your diagram carefully and estimate the slope.)−2/3.。
第一部分 消费者选择理论1.有两种商品，x1和x2，价格分别为p1和p2，收入为m 。
当11x x ≥时，政府加数量税t,画出预算集并写出预算线2. 消费者消费两种商品（x1，x2），如果花同样多的钱可以买（4，6）或（12，2），写出预算线的表达式。
3．重新描述中国粮价改革（1）假设没有任何市场干预，中国的粮价为每斤0。
4元，每人收入为100元。
把粮食消费量计为x ，在其它商品上的开支为y ，写出预算线，并画图。
（2）假设每人得到30斤粮票，可以凭票以0。
2元的价格买粮食，再写预算约束，画图。
（3）假设取消粮票，补贴每人6元钱，写预算约束并画图。
4． 证两条无差异曲线不能相交5． 一元纸币（x1）和五元纸币（x2）的边际替代率是多少？ 6．若商品1为中性商品，则它对商品2的边际替代率？7. 写出下列情形的效用函数，画出无差异曲线，并在给定价格（p 1，p 2）和收入（m ）的情形下求最优解。
（1）x 1=一元纸币，x 2=五元纸币。
（2）x 1=一杯咖啡，x 2=一勺糖, 消费者喜欢在每杯咖啡加两勺糖。
8. 解最优选择 （1）21212(,)u x x x x =⋅（2）2u x =9. 对下列效用函数推导对商品1的需求函数，反需求函数，恩格尔曲线；在图上大致画出价格提供曲线，收入提供曲线；说明商品一是否正常品、劣质品、一般商品、吉芬商品，商品二与商品一是替代还是互补关系。
（1）212x x u += （2）()212,m in x x u =（3）ba x x u 21⋅=（4） 12ln u x x =+,10.当偏好为完全替代时，计算当价格变化时的收入效用和替代效用（注意分情况讨论）。
11.给定效用函数 (,)x y xy =，p x =3，p y =4，m=60，求当p y 降为3时价格变化引起的替代效应和收入效应。
12.用显示偏好的弱公理说明为什么Slutsky 替代效应为负。
13. 设w=9元/小时，=R 18小时，m=16元，cR c R u =),( 求1）??,?,===***L c R 2）12='w 元，求'*R 和'*L14．121212(,),2000,1000,u c c c c m m ==⋅== 两期的价格都是p=1，利息率r=10%。
