微观第十章习题及答案3

第十章 一般均衡理论和福利经济学一、重点和难点 （一）重点1.局部均衡、一般均衡、帕累托最优状态2.简单的一般均衡模型3.交换的帕累托最优条件4.生产的帕累托最优条件5.生产与交换的帕累托最优条件 （二）难点1.社会福利函数与三种代表性的社会福利函数：平均主义者的社会福利函数、功利主义者的社会福利函数、罗尔斯社会福利函数 二、关键概念局部均衡分析 一般均衡分析 帕累托改进 帕累托最优状态 交换的一般均衡 产品转换率 罗尔斯社会福利标准 不可能性定理 契约曲线 福利经济学 社会无差异曲线三、习题（一）单项选择题1．当最初的变化影响广泛分散到很多市场，每个市场只受到轻微的影响时，（ ）。

A.要求用一般均衡分析B.一般均衡分析很可能推出错误的结论C.局部均衡分析很可能推出错误的结论D.局部均衡分析将提供合理可靠的预测2．被西方经济学界推崇为“福利经济学之父”的是（ ）。

A.霍布森 B.庇古 C.帕雷托 D.埃奇沃斯3．假定只存在两个人（A 和B ）、两种商品（X 和Y ）的经济中，要想达到交换全面均衡的条件是（ ）。

A.对于A 和B ，XY X Y MRS P P =B.对于A 和B ，XY XY MRS MRTS =C.对于A 和B ，A B XY XY MRS MRS =D.上面三个条件都是4．假定一个经济，在其中只有两种商品（X 和Y ），两种生产要素（L 和K ），那么要想达到生产的全面均衡的条件是（ ）。

A.LK L K MRTS P P =B.LK XY MRTS MRS =C.X YLK LK MRTS MRTS =D.XY LK MRT MRS =5．假定存在一个经济，其中有两个个人（A 和B ）、两种商品（X 和Y ），生产和交换的全面均衡条件是（ ）。

A.A BXY XY XY MRT MRS MRS ==B.X XY Y P MRT P =C.XXY YP MRS P =D.A BXY XY MRS MRS =6．小李有5个鸡蛋和5只苹果，小陈又5个鸡蛋和5只苹果，小李更喜欢鸡蛋，小陈更喜欢苹果。

复习思考题第1章 绪 论1.简述微观经济学与宏观经济学的区别与联系。

2.经济模型应该准确地描述现实世界吗？3.实证分析与规范分析的区别是什么？4.市场与行业的区别是什么？第2章 供给和需求的基本原理1.在下列各种情形下，啤酒的市场价格将如何变动？（1）啤酒生产原料价格上涨；（2）消费者收入普遍提高；（3）啤酒业进行大规模的广告宣传；（4）凉夏。

2.假设一个封闭的岛国遭受了大海啸的袭击，造成大面积农田被毁坏，但所幸的是只有很少一部分居民死亡。

请画图分析大海啸发生前后该国粮食市场均衡价格和数量的变化。

3.有人说，气候不好对农民不利，因为农业要歉收；但也有人说，气候不好对农民有利，因为农业歉收后谷物会涨价，农民因此而增收。

试利用所学的经济学原理对这两种说法给予评价。

4.刘先生决定总是把他的收入的一个固定比例（1/a ）用于购买食品。

请计算他对食品的需求价格弹性和需求收入弹性。

5.已知某一时期内某商品的需求函数为P Q d550-=，供给函数为P Q s 510+-=。

（1）求均衡价格e P 和均衡数量e Q ，并作出几何图形；（2）假定供给函数不变，由于消费者收入水平提高，使需求函数变为P Q d560-=.求出相应的均衡价格e P 和均衡数量e Q ，并作出几何图形。

（3）假定需求函数不变，由于生产技术水平提高，供给函数变为P Q s 55+-=.求出相应的均衡价格e P 和均衡数量e Q ，并作出几何图形。

6. 2006年3月1日，中国发改委等四部门联合发布通知，确定了2006年白小麦的最低收购价格为每50公斤72元。

请画图分析这种最低收购价格措施如何影响市场结果。

第3章消费者行为1.画出下述情况下消费者对牛肉汉堡包和啤酒偏好的无差异曲线：(1)李明喜欢啤酒，但厌恶汉堡包，不管他吃了多少个汉堡包，他总喜欢再多喝一点啤酒。

(2)张军对不管是3杯啤酒还是2个汉堡包的偏好是无差异的，当他多消费这两种食物中的任何一种的时候，其偏好没有变化。

习题一． 名词解释一般均衡分析 契约曲线 帕累托最优 生产可能性曲线二．选择题1．完全竞争下一般均衡的任何特点包含着以下意思( )。

A.对所有个人来说，任意两种商品的边际效用之比一定等于它们对应的边际成本之比B. 消费所有商品的边际效用相等，但是不等于每个消费者消费这些商品的边际成本C. 每种投入品的边际有形产品等于此投入品的价格D. 每种投入品的边际收益产品等于它生产的最终产品的价格2．在完全竞争一般均衡里，以下不正确的是（ ）A. 消费者的边际效用之比等于价格之比B. 两商品的边际技术替代率等于它们的价格之比C. 每种投入品的边际有形产品等于此投入品的价格D. 每种投入品的边际收益产品等于它生产的最终产品的价格3．边际转换率是 ( ) 的斜率A. 需求曲线B. 边际产品曲线C. 生产函数D. 生产可能性曲线4．生产契约曲线上的点表示生产者（ ）A. 获得了最大利润B. 支出了最小成本C. 通过生产要素的重新配置提高了总产量D. 以上均正确5．如果 社会达到生产可能性边界时， BXY MRS =A XY MRS ＜XY MRT ，则应该（ ）A. 增加XB.减少YC.增加X ，减少YD. 增加Y ，减少X6．两种商品在两个人之间的分配，能被称为帕累托最优的条件为( )A.如果不使其中一个人受损失就不能使另一个受益B. 每个人都处在其消费契约曲线上C. 每个人都处在其效用可能性曲线上D. 包括以上所有条件7．下列( )不能由帕累托效率引出A. 交换的效率B. 生产的效率C.产品组合的效率D. 所有人平等地分享收入8．当政府决定对救济接受者的收入免税时，实际上是在（ ）A.有意提高接受救济者对工作的兴趣B.帮助受救济者偷税C.减少了他们的工作热情D.在制定福利计划时的一种随意决定9．以下各条中，除了( )外，都是实现完全竞争均衡状态条件。

A. 价格等于平均成本B.对每一个人和对 其消费的每一种商品而言，边际效用与价格的比率对所有商品都是相等的C. 价格等于边际成本D.在个人间的收入分配没有显著的不平等10．在一个存在X 、Y 两种商品和L 、K 两种要素的经济体中，达到生产领域一般均衡的条件为（ ） A.K L LK P P MRTS = B.XY LK MRS MRT =C.XY XY MRS MRT =D.Y LK X LK MRTS MRTS =三．简答题1．为什么完全竞争的市场机制可以导致帕累托最优状态？2．为什么说交换的帕累托最优条件加生产的最优条件不等于交换和生产的最优条件？3．生产可能性曲线为什么向右下方倾斜？为什么向右上方突出？4．假设所考虑的经济体系由 m 个消费者、 n 个生产者、 r 种资源和 s 种产品组成。

第十章 复习题1．该垄断者减少产量，直到边际成本等于边际收益。

2．P MC P E D-=-1该等式表明，当弹性上升（需求变得更加有弹性），弹性相反数的下降和度量市场力的下降，因而当弹性上升（下降），厂商有更少（多）能力使价格高于边际成本。

3．垄断者的产出决定由需求曲线和边际成本决定。

因而需求的变动不仅像竞争的供给曲线那样给出一系列价格和产量，而且需求的变动可以导致价格改变但产量并不变，也可以导致产量改变而价格不变。

他们不存在价格和产量之间的一一对应关系，因自垄断市场没有供给曲线。

4．垄断力量的程度或一个厂商左右市场的力量取决于面对的需求曲线的弹性。

因此如果厂商的需求曲线的弹性小于无穷，厂商就有一些垄断势力。

5．来源于3个方面：（1）市场需求弹性，如，欧佩克利用石油在短期是无弹性而控制油价（2）厂商的数目，如，某3个厂商控制某一产品的市场份额，他们就有了垄断势力（3）厂商间的相互作用，如，几个主要的厂商相互串通，那么他们就能产生垄断势力。

6．同上7．垄断势力的结果是较高的价格和较低的产量，容易使消费者的利益受损,消费者剩余就会减少。

同时厂商可能用一些非生产的方式来保持他的垄断地位，从而使社会成本更大。

8． 藉由在垄断者的取利润最大值的价格下面限制价格，政府能改变厂商的边际收益曲线的形状。

当价格极高被征税的时候，边际收益为比以极高价格量低的量和极高价格相等。

如果政府取输出最大值,它应该将一个价格对手设定为边际成本。

价格在这一个水平下面引诱公司减少制造, 假定边际成本曲线正在以上难以下咽的食物。

调整者的问题要决定垄断的边际成本曲线的形状。

9. 边际的支出是在总支出方面的改变如被购买的量的变化。

对于为购买由于许多厂商竞争的一个厂商，边际的支出和平均支出相等。

所有的厂商应该购买以便最后一个单位的边际价值和在那一个单位上的边际支出相等。

这对两者的竞争买主和垄断者是真实的。

10. 买方垄断势力是购买者影响一种货物价格的能力。

尼科尔森《微观经济理论-基本原理与扩展》〔第9版〕第4篇 竞争性市场第10章 竞争性价格决定的局部均衡模型课后习题详解跨考网独家整理最全经济学考研真题，经济学考研课后习题解析资料库，您可以在这里查阅历年经济学考研真题，经济学考研课后习题，经济学考研参考书等内容，更有跨考考研历年辅导的经济学学哥学姐的经济学考研经验，从前辈中获得的经验对初学者来说是珍贵的财富，这或许能帮你少走弯路，躲开一些陷阱。

以下内容为跨考网独家整理，如您还需更多考研资料，可选择经济学一对一在线咨询进行咨询。

1．假定在完全竞争的行业中有100个完全相同的厂商。

每个厂商的短期总成本曲线为：3210.2410300C q q q =+++ 〔1〕计算作为市场价格〔P 〕的函数的厂商的短期供应曲线。

〔2〕假定行业中各厂商的成本之间不存在相互影响，请计算行业的短期供应曲线。

〔3〕假定市场需求为：2008000Q P =-+，短期的均衡价格和均衡数量的组合是什么？ 解：〔1〕因为成本为：3210.2410300C q q q =+++，所以边际成本为： ()20.010.44MC q q q =++在短期内，由P MC =，即20.010.44P q q =++，可得：20q +=从而可知厂商的短期供应曲线为：20 q =。

〔2〕假设行业中各厂商的成本之间不存在相互影响，则完全竞争行业的短期供应曲线为各厂商短期供应曲线的加总，故行业的短期供应曲线为：1002000Q q ==。

〔3〕由市场均衡，即市场需求等于市场供应可得：20080002000P -+=从而可以解得市场均衡价格为：25P =；因而市场均衡数量为：3000Q =。

此时，每个厂商的产量为：30q =，每个厂商的总成本为：400C =，所获利润为：350π=。

2．假定有1000个完全相同的厂商生产钻石，每个厂商的总成本曲线为：2C q wq =+。

其中，q 是厂商的产出水平，w 是钻石工人的工资率。

第1章绪论一、单项选择题1．经济学可定义为（）A、政府对市场制度的干预B、企业取得利润的活动C、研究如何最合理地配置稀缺资源于诸多用途D、人们靠收入生活2．经济学研究的基本问题是（）A、怎样生产B、生产什么，生产多少C、为谁生产D、以上都包括3．说“资源是稀缺的”是指（）A、世界上大多数人生活在贫困中B、相对于资源的需求而言,资源总是不足的C、资源必须保留给下一代D、世界上资源最终将由于生产更多的物品和劳务而消耗光4．人们在进行决策时，必须作出某种选择，这是因为（）A、选择会导致短缺B、人们在进行决策时面临的资源是有限的C、人是自私的，所作出的选择会实现自身利益的最大化D、个人对市场的影响是微不足道的5．下列问题（）是经济学研究不会涉及的问题A、在稀缺资源约束条件下，实现资源有效配置的方法B、如何实现中国人均收入翻两番C、中国传统文化的现代化问题D、充分就业和物价水平的稳定6．一国生产可能性曲线以内的一点表示（）A、通货膨胀B、失业或资源没有被充分利用C、该国可利用的资源减少以及技术水平降低D、一种生产品最适度水平7．下列各项中（）会导致一国生产可能性曲线向外移动A、失业B、通货膨胀C、有用性资源增加或技术进步D、消费品生产增加，资本物品生产下降8．下列命题中（）不是实证经济学命题A、1982年8月联储把贴现率降到10%B、1981年失业率超过9%C、联邦所得税对中等收入家庭是不公平D、社会保险税的课税依据已超过30 000美元9．下列（）是规范经济学的说法A、医生挣的钱比蓝领工人多B、收入分配中有太多的不公平现象C、从1999年开始，中国的物价水平基本保持稳定状态，这一现象也许会保持到2005年D、如果在20世纪80年代中期你购买了微软公司的1000股股票，现在你愿意出售的话，你肯定赚不少钱10．由市场配置资源意味着（）A、所有的人都会得到他想要的东西B、资源的配置是由市场机制实现的C、政府能够决定谁获得多少消费品D、要得到急需的物品你只能“走后门”11．西方学者认为现代美国经济是一种（）A、完全的自由放任经济制度B、严格的计划经济制度C、混合资本主义市场经济制度D、自给自足制度二、判断正误1．只有落后国家才存在资源的稀缺性和供给的短缺现象。

10.微观第十章思考题答案详解第十章思考题答案一、思考题A：1、选择题：1.1 B 解析：局部均衡指在其他市场条件不变的情况下，孤立的考察单个产品市场和单个要素市场的均衡。

1.2 A 解析：帕累托最优指的是社会资源的最优配置，实现最高效率。

1.3 C 解析：实现交换的帕累托最优的条件是两者的边际替代率相等，即ABMRSXY?MRSXY，故选C。

1.4 D 解析：实现生产的帕累托最优的条件是两者的边际技术替代率相等，即MRTSLK?MRTSLK，故选D。

1.5 D 解析：实现交换和生产的帕累托最优的条件是两者的边际替代率等于ABMRS?MRS?MRTXY，故选D。

XYXY边际转换率，即XY1.6 D 解析：要实现一个社会的帕累托最优状态必须同时满足三个条件：交换的帕累托最优、生产的帕累托最优以及交换和生产的帕累托最优。

故选D。

1.7 C解析：生产的契约曲线上的所有的点都是生产的最优均衡点，也是生产有效率的点。

当然也是通过生产要素的重新配置提高了总产量的点的集合。

故选C。

1.8 D解析：生产可能性曲线是指在其他条件（如技术、要素供给等）不变情况下，生产产品X与Y所能达到的最大产量的组合。

曲线上的每一点必会满足XYMRTSLK?MRTSLK，故选D。

11.9 D 解析：选项中A是帕累托最优的理论解释；B是交换的帕累托最优的几何解释，交换的契约曲线就是交换的帕累托最优点的集合；C是帕累托最优的效用论解释，即契约曲线转换到以效用为坐标量的平面直角图上便可得到效用可能性曲线。

实现了交换的帕累托最优当然也就实现了个人效用的最优组合。

故A、B、C都对，选D。

1.10 B 解析：转换曲线，即生产可能性曲线。

通过前面的研究推导可知，它是由生产的契约曲线导出的。

故选B。

2、简答题：（1）如果商品X的市场供给（SX）增加，按局部均衡分析，则其价格PX下降，需求量QX增加。

由于实际生活中，各种部门、各种市场是相互依存、相互制约的，X商品市场的变化会对经济的其余部分产生影响，这种影响越大，就越不适应局部均衡分析。

《西方经济学》（微观部分）习题册（第五版）学院班级姓名学号新疆财经大学经济学院西方经济学教研室2009年1月目录第一章导论 (2)第二章需求和供给以及有关的基本概念 (6)第三章效用论 (12)第四章生产理论 (18)第五章成本论 (24)第六章完全竞争市场 (29)第七章不完全竞争市场 (35)第八章生产要素价格决定的需求方面 (42)第九章生产要素价格决定的供给方面 (47)第十章一般均衡理论与福利经济学 (52)第十一章市场失灵与微观经济政策 (56)参考答案 (60)第一章导言一、单项选择题（）1. 经济学可定义为研究：A.政府对市场制度的干预B.消费者如何获取收入C.如何合理的配置稀缺资源于诸用途D.企业取得利润的活动（）2.经济学主要是研究：A.与稀缺性相关的问题B.如何在股票市场赚钱C.为什么无法作出选择D.用数学方法建立理论模型（）3.当资源不足以满足所有人的需要时：A.政府必须决定谁的要求不能被满足B.必须作出选择C.必须有一套市场系统起作用D.价格必定上升（）4. 在美国，生产什么和生产多少的问题主要取决于：A.政府和企业的相互影响B.经济中那些最大的公司C.政府的经济顾问D.企业和消费者之间私下的相互影响（）5. 经济学研究的基本问题包括：A.生产什么，生产多少B.怎样生产C.为谁生产D.以上问题均正确（）6. 商品生产给：A.想买但买不起的人B.买得起但不想买的人C.想买且买得起的人D.既不想买也买不起的人（）7、下列哪一个变量属于存量：A、国民生产总值；B、年生产能力；C、居民收入；D、固定资产价值。

（）8. 生产可能性曲线说明的基本原理是：A.一国资源总能被充分利用B.假定所有经济资源能得到充分有效利用，则只有减少一种物品的生产才能导致另一种物品生产的增加C.改进技术会引起生产可能性曲线向内移动D.经济能力增长唯一取决于劳动力的数量（）9.在中央计划体制下：A.政府涉及的基本问题仅仅是如何生产和为谁生产B.稀缺性被消灭了C.市场体制在不那么复杂的市场发挥作用D.经济学四个基本问题由政府来回答（）10. 一国生产可能性曲线以内的点表示：A.通货膨胀B.该国资源未被充分利用C.该国可被利用的资源减少D.该国生产处于最适度产出水平（）11. 下列各项中哪一项会导致一国生产可能性曲线向外移动：A.失业B.通货膨胀C.一国可利用资源增加或技术进步D.资本物品生产增加，消费品生产减少（）12. 说“资源是稀缺性的”是指：A.世界上大多数人生活在贫困中；B.相对于资源的需求而言,资源总是不足的C.资源必须保留给下一代；D.世界上资源最终将由生产更多的物品和劳务而消耗光（）13.下列哪一项是规范经济学的说法：A.医生挣的钱比蓝领工人多B.收入分配中有太多的不平等C.通货膨胀率用于衡量物价变化水平D.去年计算机的价格是2500美元（）14.经济学家对一项政府政策的效果作出预测属于：A.规范经济学分析B.宏观经济学分析C.微观经济学分析D.实证经济学分析（）15. 稀缺性意味着：A.竞争是要被消灭的B.决策者必须作出选择C.政府必须干预经济D.市场经济不能充分发挥作用二、判断题（）1.稀缺性仅仅是市场经济中存在的问题。

CHAPTER 10MARKET POWER: MONOPOLY AND MONOPSONYIn most textbooks, the title of this chapter would be “Monopoly,” and monopsony would be found in a section of the chapter on factor markets. This text, however, gives monopoly and monopsony parallel treatment. There is an initial discussion of monopoly (Sections 1-4), a briefer discussion of monopsony (Section 5), and a joint consideration of the two (Section 6). Exercises (1) through (5) focus on the monopolist’s determination of a profit-maximizing output. Exercises (6) and (7) explore the multiplant firm. Exercise (8) examines the decision in the U.S. antitrust case against Alcoa. Exercises (10) and (12) examine monopsony power. Exercises (9), (13),(14), and (15) focus on price regulation.Although previous chapters have presented the rule for profit maximization, you should briefly review marginal revenue and price elasticity of demand through a careful derivation of Equation 10.1. A discussion of the derivation of Equation 10.1 will elucidate the geometry of Figure 10.3: illustrate that because the monopolist chooses a quantity such that marginal revenue is positive, demand at that quantity is elastic. Equation 10.1 also leads directly to the Lerner Index in Section 10.2. This pro vides fruitful ground for a discussion of a monopolist’s market power. For example, if E d is large (e.g., because of close substitutes), then (1) the demand curve is flat, (2) the marginal revenue curve is flat (although steeper than the demand curve), and (3) the monopolist has little power to raise price above marginal cost. To reinforce these points, introduce a non-linear demand curve by, for example, showing the location of the marginal revenue curve for a unit-elastic demand curve. Once this concept has been clearly presented, the discussion of the effect of an excise tax on a monopolist with non-linear demand (Figure 10.5) will not seem out of place.The social response to market power provides a good topic for class discussion, and this topic can be introduced by comparing the deadweight loss with the analysis of market intervention given in Chapter 9. For example, compare Figure 10.9 with Figure 9.6. Because Exercises (9), (13), and (15) involve “kinked marginal revenue curves,” you should pres ent Figure 10.10 if you plan to assign those problems. Although Figure 10.10 is complicated, exposure to it here will help when it reappears in Chapter 12.1. When marginal cost is greater than marginal revenue, the incremental cost of the last unit produced is greater than incremental revenue. The firm would increase its profit by not producing the last unit. It should continue to reduce production, thereby decreasing marginal cost and increasing marginal revenue, until marginal cost is equal to marginal revenue.2. We can show that this measure of market power is equal to the negative inverse of the price elasticity of demand.P MC P E D-=-1 The equation implies that, as the elasticity increases (demand becomes more elastic), the inverse of elasticity decreases and the measure of market power decreases. Therefore, as elasticity increases (decreases), the firm has less (more) power to increase price above marginal cost.3. The monopolist’s output decision depends not only on mar ginal cost, but also on the demand curve. Shifts in demand do not trace out a series of prices and quantities that we can identify as the supply curve for the firm. Instead, shifts in demand lead to changes in price, output, or both. Thus, there is no one-to-one correspondence between the price and the seller’s quantity; therefore, a monopolized market lacks a supply curve.4. The degree of monopoly power or market power enjoyed by a firm depends on the elasticity of the demand curve that it faces. As the elasticity of demand increases, i.e., as the demand curve becomes flatter, the inverse of the elasticity approaches zero and the monopoly power of the firm decreases. Thus, if the firm’s demand curve has any elasticity less than infinity, the firm has some monopoly power.5. The firm’s exploitation of its monopoly power depends on how easy it is for other firms to enter the industry. There are several barriers to entry, including exclusive rights (e.g., patents, copyrights, and licenses) and economies of scale. These two barriers to entry are the most common. Exclusive rights are legally granted property rights to produce or distribute a good or service. Positive economies of scale lead to “natural monopolies” because the largest producer can charge a lower price, driving competition from the market. For example, in the production of aluminum, there is evidence to suggest that there are scale economies in the conversion of bauxite to alumina. (See U.S. v. Aluminum Company of America , 148 F.2d 416 [1945], discussed in Exercise 7, below.)6. Three factors determine the firm’s elasticity of demand: (1) the elasticity of market demand, (2) the number of firms in the market, and (3) interaction among the firms in the market. The elasticity of market demand dependson the uniqueness of the product, i.e., how easy it is for consumers to substitute away from the product. As the number of firms in the market increases, the demand elasticity facing each firm increases because customers may shift to the fir m’s competitors. The number of firms in the market is determined by how easy it is to enter the industry (the height of barriers to entry). Finally, the ability to raise the price above marginal cost depends on how other firms react to the firm’s price c hanges. If other firms match price changes, customers will have little incentive to switch to another supplier.7. When the firm exploits its monopoly power to raise the price above marginal cost, consumers buy less at the higher price. Consumers enjoy less surplus, the difference between the price they are willing to pay and the market price on each unit consumed. Some of the lost consumer surplus is not captured by the seller and is a deadweight loss to society. Therefore, if the gains to producers were redistributed to consumers, society would still suffer the deadweight loss.8. By restricting price below the monopolist’s profit-maximizing price, the government can change the shape of the firm’s marginal revenue, MR, curve. When a price ceiling is imposed, MR is equal to the price ceiling for all quantities lower than the quantity demanded at the price ceiling. If the government wants to maximize output, it should set a price equal to marginal cost. Prices below this level induce the firm to decrease production, assuming the marginal cost curve is upward sloping. The regulator’s problem is to determine the shape of the monopolist’s marginal cost curve. This task is difficult given the monopolist’s incentive to hide or distort this information.9. The marginal expenditure is the change in the total expenditure as the purchased quantity changes. For a firm competing with many firms for inputs, the marginal expenditure is equal to the average expenditure (price). For a monopsonist, the marginal expenditure curve lies above the average expenditure curve because the decision to buy an extra unit raises the price that must be paid for all units, including the last unit. All firms should buy inputs so that the marginal value of the last unit is equal to the marginal expenditure on that unit. This is true for both the competitive buyer and the monopsonist. However, because the monopsonist’s marginal expenditure curve lies above the average expenditure curve and because the marginal value curve is downward sloping, the monopsonist buys less than a firm would buy in a competitive market.10. Monopsony power is the power in the factor market held by the buyer. A buyer facing an upward-sloping factor supply curve has some monopsony power. In a competitive market, the seller faces a perfectly-elastic market curve and the buyer faces a perfectly-elastic supply curve. Thus, any characteristic of the market (e.g., when there is a small number of buyers or if buyers engage in collusive behavior) that leads to a less-than-perfectly-elastic supply curve gives the buyer some monopsony power.11. The individual firm’s monopsony power depends on the characteristics of the “buying-side” of the market. There are three characteristics that enhance monopsony power: (1) the elasticity of market supply, (2) the number of buyers, and (3) how the buyers interact. The elasticity of market supply depends on how responsive producers are to changes in price. If, in the short run, supply is relatively fixed, then supply is relatively inelastic. For example, since tobacco farmers can sell their crop to only a handful of tobacco product producers, the power to buy at a price below marginal value is increased.12. With monopsony power, the price is lower and the quantity is less than under competitive buying conditions. Because of the lower price and reduced sales, sellers lose revenue. Only part of this lost revenue is transferred to the buyer as consumer surplus, and the net loss in total surplus is deadweight loss. Even if the consumer surplus could be redistributed to sellers, the deadweight loss persists. This inefficiency will remain because quantity is reduced below a level where price is equal to marginal cost.13. Antitrust laws, which are subject to interpretation by the courts, limit market power by proscribing a firm’s behavior in attempting to maximize profit. Section 1 of the Sherman Act prohibits every restraint of trade, including any attempt to fix prices by buyers or sellers. Section 2 of the Sherman Act prohibits behavior that leads to monopolization. The Clayton Act, with the Robinson-Patman Act, prohibits price discrimination and exclusive dealing (sellers prohibiting buyers from buying goods from other sellers). The Clayton Act also limits mergers when they could substantially lessen competition. The Federal Trade Commission Act makes it illegal to use unfair or deceptive practices.14. Antitrust laws are enforced in three ways: (1) through the Antitrust Division of the Justice Department, whenever firms violate federal statutes, (2) through the Federal Trade Commission, whenever firms violate the Federal Trade Commission Act, and (3) through civil suits. The Justice Department can seek to impose fines or jail terms on managers or owners involved or seek to reorganize the firm, as it did in its case against A.T.& T. The FTC can seek a voluntary understanding to comply with the law or a formal Commission order. Individuals or companies can sue in federal court for awards equal to three times the damage arising from the anti-competitive behavior.1. As illustrated in Figure 10.4b in the textbook, an increase in demand need not always result in a higher price. Under the conditions portrayed in Figure 10.4b, the monopolist supplies different quantities at the same price. Similarly, an increase in supply facing the monopsonist need not always result in a higher price. Suppose theaverage expenditure curve shifts from AE 1 to AE 2, as illustrated in Figure 10.1. With the shift in the average expenditure curve, the marginal expenditure curve shifts from ME 1 to ME 2. The ME 1 curve intersects the marginal value curve (demand curve) at Q 1, resulting in a price of P . When the AE curve shifts, the ME 2 curve intersects the marginal value curve at Q 2 resulting in the same price at P .Figure 10.12. As a large producer of farm equipment, Caterpillar Tractor has market power and should consider the entire demand curve when choosing prices for its products. As their advisor, you should focus on the determination of the elasticity of demand for each product. There are three important factors to be considered. First, how similar are the products offered by Caterpillar’s competitors? If they are close substitutes, a small incr ease in price could induce customers to switch to the competition. Secondly, what is the age of the existing stock of tractors? With an older population of tractors, a 5 percent price increase induces a smaller drop in demand. Finally, because farm tractors are a capital input in agricultural production, what is the expected profitability of the agricultural sector? If farm incomes are expected to fall, an increase in tractor prices induces a greater decline in demand than one would estimate with information on only past sales and prices.3. Yes. The monopolist’s pricing rule as a function of the elasticity of demand for its product is:(P -MC)P = - 1E dor alternatively,d E 1 + 1MC= P ⎪⎪⎪⎭⎫ ⎝⎛⎪⎪⎪⎭⎫ ⎝⎛In this example E d = -2.0, so 1/E d = -1/2; price should then be set so that:2MC = 21MC = P ⎪⎪⎭⎫ ⎝⎛ Therefore, if MC rises by 25 percent price, then price will also rise by 25 percent. When MC = $20, P = $40. When MC rises to $20(1.25) = $25, the price rises to $50, a 25% increase.4. a. The profit-maximizing output is found by setting marginal revenue equal to marginal cost. Given a linear demand curve in inverse form, P = 100 - 0.01Q , we know that the marginal revenue curve will have twice the slope of the demand curve. Thus, the marginal revenue curve for the firm is MR = 100 - 0.02Q . Marginal cost is simply the slope of the total cost curve. The slope of TC = 30,000 + 50Q is 50. So MC equals 50. Setting MR = MC to determine the profit-maximizing quantity:100 - 0.02Q = 50, orQ = 2,500.Substituting the profit-maximizing quantity into the inverse demand function to determine theprice:P = 100 - (0.01)(2,500) = 75 cents.Profit equals total revenue minus total cost:π = (75)(2,500) - (30,000 + (50)(2,500)), orπ = $325 per week.b.Suppose initially that the consumers must pay the tax to the government. Since the total price (including the tax) consumers would be willing to pay remains unchanged, we know that the demand function isP* + T = 100 - 0.01Q, orP* = 100 - 0.01Q - T,where P* is the price received by the suppliers. Because the tax increases the price of each unit, total revenue for the monopolist decreases by TQ, and marginal revenue, the revenue on each additional unit, decreases by T:MR = 100 - 0.02Q - Twhere T = 10 cents. To determine the profit-maximizing level of output with the tax, equate marginal revenue with marginal cost:100 - 0.02Q - 10 = 50, orQ = 2,000 units.Substituting Q into the demand function to determine price:P* = 100 - (0.01)(2,000) - 10 = 70 cents.Profit is total revenue minus total cost:()()()()()000,100000,30000,250000,270=+-=πcents, or$100 per week.Note: The price facing the consumer after the imposition of the tax is 80 cents. The monopolist receives 70 cents. Therefore, the consumer and the monopolist each pay 5 cents of the tax.If the monopolist had to pay the tax instead of the consumer, we would arrive at the same result. The monopolist’s cost function would then beTC = 50Q + 30,000 + TQ = (50 + T)Q + 30,000.The slope of the cost function is (50 + T), so MC = 50 + T. We set this MC to the marginal revenue function from part (a):100 - 0.02Q = 50 +10, orQ = 2,000.Thus, it does not matter who sends the tax payment to the government. The burden of the tax is reflected in the price of the good.5. a.To find the marginal revenue curve, we first derive the inverse demand curve. The intercept of the inverse demand curve on the price axis is 27. The slope of the inverse demand curve is the change in price divided by the change in quantity. For example, a decrease in price from 27 to 24 yields an increase in quantity from 0 to 2.Therefore, the slope is -32and the demand curve isP Q=-2715..The marginal revenue curve corresponding to a linear demand curve is a line with the same intercept as the inverse demand curve and a slope that is twice as steep. Therefore, the marginal revenue curve isMR = 27 - 3Q.b.The monopolist’s maximizing output occurs where marginal revenue equals marginal cost. Marginal cost is a constant $10. Setting MR equal to MC to determine the profit-maximizing quantity:27 - 3Q = 10, or Q=567..To find the profit-maximizing price, substitute this quantity into the demand equation:()().5.18$67.55.127=-=PTotal revenue is price times quantity:()().83.104$67.55.18==TRThe profit of the firm is total revenue minus total cost, and total cost is equal to average cost times the level of output produced. Since marginal cost is constant, average variable cost is equal to marginal cost. Ignoring any fixed costs, total cost is 10Q or 56.67, and profit is10483566717..$48..-=c.For a competitive industry, price would equal marginal cost at equilibrium. Setting the expression for priceequal to a marginal cost of 10:271510-=.Q , or Q =1133..Note the increase in the equilibrium quantity compared to the monopoly solution.d.The social gain arises from the elimination of deadweight loss. Since deadweight loss under monopoly is equal to the difference between the price under monopoly minus the price under competition (18.5 - 10 = 8.5) times the difference between the quantity under competition minus the quantity under monopoly (11.3 - 5.67 = 5.67) times one-half, the deadweight loss is a triangle under the demand curve:(0.5)(8.5)(5.67) = $24.10.Furthermore, consumers gain this deadweight loss plus the monopolist’s profit of $48. The monopolist’s profits are reduced to zero, and the consumer surplus increases by $72.6. a. The average revenue curve is the demand curve,P = 700 - 5Q .For a linear demand curve, the marginal revenue curve has the same intercept as the demand curve and a slope that is twice as steep:MR = 700 - 10Q .Next, determine the marginal cost of producing Q . To find the marginal cost of production in Factory 1, take the first derivative of the cost function with respect to Q :().20111Q dQQ dC = Similarly, the marginal cost in Factory 2 is().40222Q dQQ dC = Rearranging the marginal cost equations in inverse form and horizontally summing them, we obtain total marginal cost, MC T :Q Q Q MC MC MC T =+=+=12122040340, orMC Q T =403. Profit maximization occurs where MC T = MR . See the Figure 10.6.a for the profit-maximizing output for each factory, total output, and price.Figure 10.6.ab.Calculate the total output that maximizes profit, i.e., Q such that MC T = MR :40370010Q Q =-, or Q = 30. Next, observe the relationship between MC and MR for multiplant monopolies:MR = MC T = MC 1 = MC 2.We know that at Q = 30, MR = 700 - (10)(30) = 400.Therefore,MC 1 = 400 = 20Q 1, or Q 1 = 20 andMC 2 = 400 = 40Q 2, or Q 2 = 10.To find the monopoly price, P M , substitute for Q in the demand equation:This means that the demand curve becomes P = 20 - 3Q 2. With an inverse linear demand curve, we know that the marginal revenue curve has the same vertical intercept but twice the slope, or MR = 20 - 6Q 2. To determine the profit-maximizing level of output, equate MR and MC 2:20 - 6Q 2 = 10 + 5Q 2, orQ Q ==2091..Price is determined by substituting the profit-maximizing quantity into the demand equation:()3.1791.0320=-=P .8. a. Although Alcoa controlled about 90 percent of primary aluminum production in the United States, secondary aluminum production by recyclers accounted for 30 percent of the total aluminum supply. Therefore, with a higher price, a much larger proportion of aluminum supply could come from secondary sources. This assertion is true because there is a large stock of potential supply in the economy. Therefore, the price elasticity of demand for Alcoa’s primary aluminum is much higher than we would expect, given Alcoa’s domi nant position in primary aluminum production. In many applications, other metals such as copper and steel are feasible substitutes for aluminum. Again, the demand elasticity Alcoa faces might be lower than we would otherwise expect.b.While Alcoa could not raise its price by very much at any one time, the stock of potential aluminum supply is limited. Therefore, by keeping a stable high price, Alcoa could reap monopoly profits. Also, since Alcoa had originally produced the metal reappearing as recycled scrap, it would have considered the effect of scrap reclamation on future prices. Therefore, it exerted effective monopolistic control over the secondary metal supply.c.Judge Hand ruled against Alcoa but did not order it to divest itself of any of its United States production facilities. The two remedies imposed by the court were (1) that Alcoa was barred from bidding for two primary aluminum plants constructed by the government during World War II (they were sold to Reynolds and Kaiser) and (2) that it divest itself of its Canadian subsidiary, which became Alcan.9. a. Because demand (average revenue) may be described as P = 11 - Q , we know that the marginal revenue function is MR = 11 - 2Q . We also know that if average cost is constant, then marginal cost is constant and equal to average cost: MC = 6.To find the profit-maximizing level of output, set marginal revenue equal to marginal cost:11 - 2Q = 6, or Q = 2.5.That is, the profit-maximizing quantity equals 2,500 units. Substitute the profit-maximizingquantity into the demand equation to determine the price:P = 11 - 2.5 = $8.50.Profits are equal to total revenue minus total cost,π = TR - TC = (AR )(Q ) - (AC )(Q ), orπ = (8.5)(2.5) - (6)(2.5) = 6.25, or $6,250. The degree of monopoly power is given by the Lerner Index:P MC-=-=8560294... b.To determine the effect of the price ceiling on the quantity produced, substitute the ceiling price into the demandequation.7 = 11 - Q , orQ = 4,000.This quantity is the profit-maximizing level of output for the monopolist because, at that level,MR = MC .Profits are equal to total revenue minus total cost:π = (7)(4,000) - (6)(4,000) = $4,000. The degree of monopoly power is:P MC -=-=760143.. c.If the regulatory authority sets a price below $6, the monopolist would prefer to go out of business instead of produce because it cannot cover its average costs. At any price above $6, the monopolist would produce less than the 5,000 units that would be produced in a competitive industry. Therefore, the regulatory agency should set a price ceiling of $6, thus making the monopolist face a horizontal effective demand curve up to Q = 5,000. To ensure a positive output (so that the monopolist is not indifferent between producing 5,000 units and shutting down), the price ceiling should be set at $6 + δ, where δ is small.Thus, 5,000 is the maximum output that the regulatory agency can extract from the monopolistby using a price ceiling. The degree of monopoly power isP MC P -=+-=→66660δδ as δ → 0. 10.a. M MMT should offer enough t-shirts such that MR = MC . In the short run, marginal cost is the change in SRTC as the result of the production of another t-shirt, i.e.,SRMC = 5, the slope of the SRTC curve. Demand is:Q P =100002,, or, in inverse form,P = 100Q-1/2. Total revenue (PQ ) is 100Q 1/2. Taking the derivative of TR with respect to Q , MR = 50Q -1/2. Equating MR and MC to determine the profit-maximizing quantity:5 = 50Q -1/2, or Q = 100.Substituting Q = 100 into the demand function to determine price:P = (100)(100-1/2 ) = 10.The profit at this price and quantity is equal to total revenue minus total cost:π = (10)(100) - (2000 + (5)(100)) = -$1,500.Although profit is negative, price is above the average variable cost of 5 and therefore, the firm should not shut down in the short run. Since most of the firm’s costs are fixed, the firm loses $2,000 if nothing is produced. If the profit-maximizing quantity is produced, the firm loses only $1,500.b.In the long run, marginal cost is equal to the slope of the LRTC curve, which is 6.Equating marginal revenue and long run marginal cost to determine the profit-maximizing quantity:50Q -1/2 = 6 or Q = 69.44Substituting Q = 69.44 into the demand equation to determine price:P = (100)[(50/6)2] -1/2 = (100)(6/50) = 12Therefore, total revenue is $833.33 and total cost is $416.67. Profit is $416.67. The firm should remain in business.c.In the long run, MMMT must replace all fixed factors. Therefore, we can expect LRMC to be higher than SRMC .11. No, production should not shift to the Massachusetts plant, although production in the Connecticut plant should be reduced. In order to maximize profits, a mulitplant firm will schedule production at all plants so that the following two conditions are met:- Marginal costs of production at each plant are equal.- Marginal revenue of the total amount produced is equal to the marginal cost at each plant.These two rules can be summarized as MR = MC1 = MC2= MC3, where the subscript indicates the plant.The firm in this example has two plants and is in a perfectly competitive market. In a perfectly competitive market P = MR. To maximize profits, production among the plants should be allocated such that:(10,000)(n), and marginal expenditure is 10,000. Equating marginal value and marginal expenditure:30,000 - 125n = 10,000, orn = 160.13. a. To maximize profits, DD should equate marginal revenue and marginal cost. Given a demand of P = 55 - 2Q, we know that total revenue, PQ, is 55Q - 2Q2. Marginal revenue is found by taking the first derivative of total revenue with respect to Q or:MRdTRdQQ ==-554.Similarly, marginal cost is determined by taking the first derivative of the total cost function with respect to Q or:MCdTCdQQ==-2 5.Equating MC and MR to determine the profit-maximizing quantity,55 - 4Q = 2Q - 5, orQ = 10.Substituting Q = 10 into the demand equation to determine the profit-maximizing price:P = 55 - (2)(10) = $35.Profits are equal to total revenue minus total cost:π = (35)(10) - (100 - (5)(10) + 102) = $200.Consumer surplus is equal to one-half times the profit-maximizing quantity, 10, times thedifference between the demand intercept (the maximum price anyone is willing to pay) and themonopoly price:CS = (0.5)(10)(55 - 35) = $100.b.In competition, profits are maximized at the point where price equals marginal cost, where price is givenby the demand curve:55 - 2Q = -5 + 2Q, orQ = 15.Consumer surplus isCS = (0.5)(55 - 27)(14) = $196.Profits areπ = (27)(14) - (100 - (5)(14) + 142) = $152.The deadweight loss is $2.00 This is equivalent to a triangle of(0.5)(15 - 14)(27 - 23) = $2e.With a ceiling price set below the competitive price, DD will decrease its output. Equate marginal revenue and marginal cost to determine the profit-maximizing level of output:23 = - 5 + 2Q, or Q = 14.With the government-imposed maximum price of $23, profits areπ = (23)(14) - (100 - (5)(14) + 142) = $96.Consumer surplus is realized on only 14 doorsteps. Therefore, it is equal to the consumersurplus in part d., i.e. $196, plus the savings on each doorstep, i.e.,CS = (27 - 23)(14) = $56.Therefore, consumer surplus is $252. Deadweight loss is the same as before, $2.00.f.With a maximum price of only $12, output decreases even further:12 = -5 + 2Q, or Q = 8.5.Profits areπ = (12)(8.5) - (100 - (5)(8.5) + 8.52) = -$27.75.Consumer surplus is realized on only 8.5 units, which is equivalent to the consumer surplusassociated with a price of $38 (38 = 55 - 2(8.5)), i.e.,(0.5)(55 - 38)(8.5) = $72.25plus the savings on each doorstep, i.e.,(38 - 12)(8.5) = $221.Therefore, consumer surplus is $293.25. Total surplus is $265.50, and deadweight loss is $84.50.11。

第一章导论一、选择题（共9个）1．经济学中的“稀缺性”是指A．世界上大多数人生活在贫困中B．相对于资源的需求而言，资源总是不足的C．利用资源必须考虑下一代D．世界上的资源终将被人类消耗光2．经济物品是指A．有用的物品B．数量有限，要花费代价才能得到的物品C．稀缺的物品D．数量无限，不用付出代价就能得到的物品3．一国的生产可能性曲线以内的点表示A．生产品最适度水平B．该国可利用的资源减少和技术水平降低C．失业或资源未被充分利用D．通货膨胀4．生产可能曲线的基本原理是A．假定所有资源得到了充分利用B．一国资源总能被充分利用C．改进技术引起生产可能曲线向内移动D．生产可能曲线上的每一点的产品组合，对该国来说，都是最佳的5．下列那一项最可能导致生产可能性曲线向外移动A．消费品生产增加，资本品生产减少B．有用性资源增加或技术进步C．通货膨胀；D．失业6．经济学中的基本选择包括A．生产什么，生产多少B．怎样生产，何时生产C．为谁生产D．以上都包括7．对某个汽车生产企业来说，下列哪一变量是外生变量A．汽车的年产量B．生产线的技术水平C．消费者收入增加D．企业的人力资本管理8．下列哪一个变量属于存量（）A．国民生产总值B．年生产能力C．居民收入D．固定资产价值9．21世纪30年代，西方经济学经历的第二次修改和补充A．出现于1936年B．涉及垄断问题C．代表人物是凯恩斯D．为国家干预经济生活奠定了理论基础二、判断题（共1个）1．以萨缪尔森为首的新古典综合派把经济学分为微观经济学和宏观经济学。

三、解释概念（共17个）1．经济学2．欲望3.稀缺性4.选择5.机会成本6.生产可能性曲线7.经济人假定8.完全信息9.个量分析10总量分析11.静态分析12．动态分析13.实证分析14.规范分析15.常量与变量16.存量与流量17.内生变量与外生变量第一章习题答案一、选择题（共9个）二、判断题（共1个）三、解释概念（共17个）（略）第二章需求、供给和均衡价格一、选择题（共18个）1．微观经济学的的基本假设条件是：A．完全信息的假设B．完全竞争的假设C．合乎理性的人的假设D．边际效用递减的假设2．微观经济学的研究对象包括：A．单个消费者B．单个厂商C．单个市场D．价格理论3．下列几组商品的交叉价格弹性为负向的有：A．面粉和大米B．汽油和汽车C．羊肉和牛肉D．CD播放机和CD4．当出租车租金下调后,对公共汽车服务的A．需求减少B．需求量增加C．需求曲线左移D．需求无法确定5．粮食市场的需求是缺乏弹性的，当粮食产量因灾害而减少时A．粮食生产者的收入减少，因粮食产量下降B．粮食生产者的收入增加，因粮食价格会更大幅度上升C．粮食生产者的收入减少，因粮食需求量会大幅度减少D．粮食生产者的收入不变，因粮食价格上升与需求量减少的比率相同6．列商品中,需求价格弹性最大的是A．服装B．化妆品C．金银首饰D．食盐7．某一时期，电冰箱的供给曲线向右移动的原因可以是A．电冰箱的价格下降B．生产者对电冰箱的预期价格上升C．生产冰箱的要素成本上升D．消费者的收入上升8．食盐市场的需求是缺乏弹性的，由于某种非价格因素的影响使食盐产量下降20%，在这种情况下A．食盐生产者的收入减少，因为食盐产量下降20%B．食盐生产者的收入增加，因为食盐价格上升低于20%C．食盐生产者的收入增加，因为食盐价格上升超过20%D．食盐生产者的收入不变，因为食盐价格上升等于20%9．影响一种商品需求数量的因素包括A．商品本身的价格B．消费者的收入水平C．相关商品的价格D．消费者的偏好10．消费者预期某物品未来价格要上升，则对该物品的当前需求会A．减少B．增加C．不变D．以上三种情况都有可能11．如果商品A和商品B是替代品，则A的价格下降将造成A．A的需求曲线向右移动B．A的需求曲线向左移动C．B的需求曲线向右移动D．B的需求曲线向左移动12．若某行业中许多生产者生产一种标准化产品，我们可估计到其中任何一个生产者产品的需求将是A．毫无弹性B．有单位弹性C．缺乏弹性或弹性较小D．富有弹性或弹性很大13．假如生产某种产品所需原料价格上升了，则这种商品A．需求曲线向左移动B．供给曲线向左移动C．需求曲线向右移动D．供给曲线向右移动14．如果人们收入水平提高，则食品支出在总支出中的比重A．提高B．降低C．不变D．不确定15．厂商在工资率下降的时候一般倾向于增雇工人，如果对工人的需求缺乏弹性，工资率下降将导致工资总额A．减少B．不变C．增加D．无法确定16．政府为了扶持农业，对农产品规定了高于均衡价格的支持价格。