西方经济学课后练习答案第七章
微观第七章习题一、名词解释完全垄断市场垄断竞争市场寡头市场价格歧视博弈纳什均衡占优策略均衡二、选择题1、对于垄断厂商来说，（）。
A、提高价格一定能够增加收益； B 、降低价格一定会减少收益；C、提高价格未必会增加收益，降低价格未必会减少收益； D 、以上都不对。
2、完全垄断的厂商实现长期均衡的条件是（）。
A、MR=M；C B 、MR=SMC=LM；C C 、MR=SMC=LMC=S；AC D、MR=SMC=LMC=SAC=。
LAC3、完全垄断厂商的总收益与价格同时下降的前提条件是（）。
A、Ed>1；B、Ed<1；C、Ed=1；D、Ed=0。
4、完全垄断厂商的产品需求弹性Ed=1 时（）。
A、总收益最小；B、总收益最大；C、总收益递增；D、总收益递减。
5、完全垄断市场中如果A市场的价格高于B 市场的价格，则（）A、A市场的需求弹性大于B 市场的需求弹性；B、A市场的需求弹性小于B 市场的需求弹性；C、A市场的需求弹性等于B 市场的需求弹性；D、以上都对。
6、以下关于价格歧视的说法不正确的是（）。
A、价格歧视要求垄断者能根据消费者的支付意愿对其进行划分；B、一级价格歧视引起无谓损失；C、价格歧视增加了垄断者的利润；D、垄断者进行价格歧视，消费者就必定不能进行套利活动。
7、垄断竞争的厂商短期均衡时，（）。
A、一定能获得差额利润；B 、一定不能获得经济利润；C、只能得到正常利润； D 、取得经济利润、发生亏损和获得正常利润都有可能。
8、垄断竞争厂商长期均衡点上，长期平均成本曲线处于（ B ）A、上升阶段 B 、下降阶段C、水平阶段 D 、以上三种情况都有可能9、垄断竞争厂商实现最大利润的途径有：（D ）A 、调整价格从而确定相应产量B、品质竞争C、广告竞争D、以上途径都可能用10、按照古诺模型下列哪一说法不正确，（）。
A、双头垄断者没有认识到他们的相互依耐性； B 、每一个寡头都认定对方的产量保持不变；C 、每一个寡头垄断者都假定对方价格保持不变；D 、均衡的结果是稳定的。
11、斯威齐模型是（）A、假定一个厂商提高价格，其他厂商就一定跟着提高价格；B、说明为什么每个厂商要保持现有的价格，而不管别的厂商如何行动；C、说明为什么均衡价格是刚性的（即厂商不肯轻易的变动价格）而不是说明价格如何决定；D、假定每个厂商认为其需求曲线在价格下降时比上升时更具有弹性。
12、在拐折的需求曲线模型中，拐点左右两边的弹性是（）。
A、左边弹性大，右边弹性小； B 、左边弹性小，右边弹性大；C、两边弹性一样大； D 、以上都不对。
13、与垄断相关的无效率是由于（）。
A、垄断利润B、垄断亏损C、产品的过度生产D、产品的生产不足。
三、判断题1、垄断厂商后可以任意定价。
2、完全垄断企业的边际成本曲线就是它的供给曲线。
3、一级价格歧视是有市场效率的，尽管全部的消费者剩余被垄断厂商剥夺了。
4、许多学院和大学对贫困学生提供奖学金。
可以认为这种政策是一种价格歧视5、垄断厂商生产了有效产量，但它仍然是无效率的，因为它收取的是高于边际成本的价格，获取的利润是一种社会代价。
6、完全垄断厂商处于长期均衡时，一定处于短期均衡。
7、垄断竞争厂商的边际收益曲线是根据其相应的实际需求曲线得到的。
8、由于垄断厂商的垄断地位保证了它不管是短期还是长期都可以获得垄断利润。
四、计算题1、已知某垄断者的成本函数为TC=+10Q，产品的需求函数为P=，（1）计算利润最大化时候的产量、价格和利润；（2）假设国内市场的售价超过P=55 时，国外同质的产品将输入本国，计算售价时垄断者可以销售的数量和赚得的利润；（3）假设政府根据P=MC的原则制定的国内最高售价P=50，垄断者会提供的产量和利润各为多少？国内市场是否会出现经济需求引起的短缺？p=552、垄断竞争市场中一厂商的长期总成本函数为：LTC=；LTC长期总成本，Q 表示月产量，不存在进入障碍，产量由整个产品集团调整。
若产量集团中所有的厂商按照同比例的调整价格，出售产品的实际需求曲线为：Q=，这里Q是月产量，P 商品的售价；（1）计算厂商长期均衡产量和价格；（2）计算厂商主观需求曲线上长期均衡点的弹性；（3）若厂商的主观需求曲线是线性的导出厂商的长期均衡时的主观需求曲线。
3、垄断竞争市场中代表性厂商的长期成本函数为LTC=，需求曲线为P=（其中A 可认为是生产集团中厂商人数的函数），实现长期均衡时需求曲线与长期平均成本曲线相切，求长期均衡条件下代表性厂商的均衡价格和产量，以及相应的A 值。
4、假设有两个寡头厂商的行为遵循古诺模型，它们的成本函数分别为：TC1=+20Q1+100000,TC2=+32Q2+20000，其市场需求曲线为Q=4000-10P，根据古诺模型，试求：（1）厂商1 和厂商2 的反应函数；（2）厂商1 和厂商2的均衡价格和均衡产量；（3）厂商1 和厂商2 的利润。
5、某垄断厂商在甲乙两地进行销售，在甲地的边际收益曲线是MR1=37-3Q1，在乙地的边际收益曲线是MR2=40-2Q2，该厂商的边际成本为16 ，固定成本为150，求利润最大化时的两地销售量以及最大的利润为多少？五、简答题1、垄断厂商一定能获得经济利润吗？如果短期内垄断厂商在最优产量处生产出现亏损，他仍然会继续生产吗？在长期内又如何呢？2、比较完全竞争厂商的长期均衡与垄断厂商的长期均衡。
3、垄断厂商实施的三级价格歧视时的价格和产量是如何确定的？4 、试述古诺模型的主要内容和结论.5、为什么需求的价格弹性较高，导致垄断竞争厂商进行非价格竞争？6、为什么垄断者生产的产量总会少于社会有效的产量呢？7、在博弈论中，占优策略均衡总是纳什均衡吗？纳什均衡一定是占优策略均衡吗？六、作图分析题1、作图分析垄断厂商短期亏损时的情况，并简要说明经济含义。
2、作图分析垄断竞争厂商长期均衡的状态。
3、作图说明弯折的需求曲线模型是如何解释寡头市场上的价格刚性现象的。
微观第七章习题答案、略选择题CBBBB DDBDC CAD1、C.2、B.13、 B. 由于总收益下降，则边际收益为负。
且MR P 1 1E d14、B.由MR P 1 E，可知，当E d 1时，MR=0，所以此时总收益最大。
Ed5、 B.完全垄断厂商实行价格歧视是在需求价格弹性小的市场上提高价格，而在需求价格弹性大的市场上降低价格。
6、D.7、D.8、 B. 垄断竞争厂商长期均衡点是其主观需求曲线与LAC曲线的切点。
由于其具有一定的垄断力对价格有一定的控制能力，所以其需求曲线是一条向右下方倾斜的曲线，其与LAC曲线的切点当然也就位于LAC曲线最低点的左边，即LAC曲线的下降阶段。
9、D．10、C.11、C.12、A.13、 D. 垄断势力的存在使厂商可以维持低产高价，从而使资源配置无效率。
三、判断题××√√√√××1、×。
2、×。
垄断厂商没有确定的供给曲线。
3、√。
一级价格歧视下，虽然所有的消费者剩余都被厂商剥夺了，但是其均衡的价格和产量与完全竞争下的均衡价格和产量一样，所以其资源配置是有效率的。
4、√5、√6、√7、×。
垄断竞争厂商的边际收益曲线是根据其相应的主观需求曲线得到的。
8、×。
短期内垄断厂商既可能获得经济利润也可能经济利润为0，还可能出现亏损。
四、计算题1、已知某垄断者的成本函数为TC=+10Q，产品的需求函数为P=，（1）计算利润最大化时候的产量、价格和利润；（2）假设国内市场的售价超过P=55 时，国外同质的产品将输入本国，计算售价p=55时垄断者可以销售的数量和赚得的利润；（3）假设政府根据P=MC的原则制定的国内最高售价P=50，垄断者会提供的产量和利润各为多少？国内市场是否会出现经济需求引起的短缺？解：（1）垄断厂商利润最大化：MR=M，C 已知TC可得MC=Q+1；0 又TR=（）Q 可得MR=90-Q；于是：MR=MC即Q+10=90-Q，解之Q=40；将Q=40 带入需求函数，解之P=70；利润π=TR-TC=1600（2）当P=55 时，即=55 得，Q=70；当Q=70时，TC=3150；TR=P*Q=3850π=TR-TC=700；（3）假设国家最高限价P=50，这实际上是对垄断厂商采取了边际成本定价的原则即P=MC；此时厂商提供的产量为Q=40；厂商的利润为π=TR-TC=800；然而此时市场的需求根据需求函数计算得Q=80，故会出现市场供不应求的局面。
2、垄断竞争市场中一厂商的长期总成本函数为：LTC=；LTC长期总成本，Q 表示月产量，不存在进入障碍，产量由整个产品集团调整。
若产量集团中所有的厂商按照同比例的调整价格，出售产品的实际需求曲线为：Q=，这里Q是月产量，P 商品的售价；（1）计算厂商长期均衡产量和价格；（2）计算厂商主观需求曲线上长期均衡点的弹性；（3）若厂商的主观需求曲线是线性的导出厂商的长期均衡时的主观需求曲线。
解：（1）由LTC可推知：：LAC=由Q=可知，P= 长期均衡时，实际需求曲线必然和LAC曲线在均衡点上相交，令LAC=P则有，解之得Q=200，P=40（2）长期均衡时，主观需求曲线必然和LAC 曲线相切，且MR=MC由LTC得LMC= 当Q=200时，LMC=35，因此，MR=35；运用公式可求的弹性1MR P（1 ）ed可求得e d 为8。
（3）由于主观需求曲线被假定为直线，假定其函数形式为：P A BQ由上面计算有：当从价格从40增加到A时，厂商的产量从200 下降为0.0 200则根据需求价格弹性的定义有：e d200 40 8 A 45 ，d A P A 40P而再将P 40,Q 200,A 45代入主观需求函数P=A-BQ中可得主观需求曲线的斜率为：B A P 45 40 0.025，Q 200于是可得到主观反需求函数为：P=。
变换形式有主观需求函数为：Q 1800 40P150371 23、垄断竞争市场中代表性厂商的长期成本函数为LTC=，需求曲线为 P=（其中 A 可认为是生产集团中厂商人数的函数） ，实现长期均衡时需求曲线与长期平均成本曲线相切，求 长期均衡条件下代表性厂商的均衡价格和产量，以及相应的A 值。
解：由 LTC 0.0025Q 3 0.5Q 2 384Q LAC 0.0025Q 2 0.5Q 384又由于厂商上期均衡时，其需求曲线与长期平均成本曲线相切0.1dLAC 0.1 0.005Q0.5 Q 80dQ所以， P LAC 20.0025 80 20.5 80 384 360 再将 Q80，P360代入 P A 0.1Q A 3684、 假设有两个 寡头厂 商的 行为遵 循古诺 模型， 它们的成本 函数分 别为 ： TC 1=+20Q 1+100000,TC2=+32Q 2+20000，其市场需求曲线为 Q=4000-10P ，根据古诺模型， 试求： （1）厂商 1 和厂商 2 的反应函数； （ 2）厂商 1 和厂商 2的均衡价格和均衡产量； （3）厂商 1 和厂商 2 的利润。
西方经济学（微观部分）第七章非完全竞争市场习题
西⽅经济学（微观部分）第七章⾮完全竞争市场习题第七章⾮完全竞争市场⼀、选择题1、以下最不可能成为垄断者的是（）A．⼀个⼩镇上惟⼀的⼀名医⽣ B．可⼝可乐公司C．某地区的电⼒公司 D．某地区的⾃来⽔公司2、下列不能成为进⼊⼀个⾏业的壁垒的是（）A．垄断利润 B．⽴法 C．专利权D．资源控制3、垄断⼚商拥有控制市场的权⼒，这意味着（）A．垄断⼚商⾯对⼀条向下倾斜的需求曲线B．如果他的产品增加⼀个单位，则全部产品的销售价格必须降低C．垄断⼚商的边际收益曲线低于其需求曲线D．以上都对4、在竞争性市场和垄断市场中，下列哪种情况下⼚商将扩⼤其产出⽔平？（）A．价格低于边际成本 B．价格⾼于边际成本C．边际收益低于边际成本 D．边际收益⾼于边际成本5、当成本相同时，垄断⼚商和竞争性⼚商⼀致的是（）A．利润最⼤化⽬标 B．产出⽔平C．长期中的经济利润 D．⽣产的有效率6、⼀个垄断⼚商在长期中⼀直获得经济利润，那么（）A．该⼚商的⽣产⽐竞争性市场的⼚商更有效率B．其他⼚商⽆法进⼊该⾏业与其竞争C．政府和垄断⼚商之间必定串谋来维持⼀个⾼价格D．垄断⼚商的需求曲线缺乏弹性，从⽽使得其获得更多的收益7、当垄断竞争⼚商处在长期均衡点时，长期平均成本曲线处于（）A．上升阶段 B．下降阶段C．⽔平阶段 D．以上三种情况都可能8、垄断竞争市场上⼚商的短期均衡发⽣于（）A．边际成本等于实际需求曲线产⽣的边际收益时B．平均成本下降时C．主观需求曲线与实际需求曲线相交，并有边际成本等于主观需求曲线产⽣的边际收益时D．主观需求曲线与平均成本曲线相切时9、寡头垄断和垄断竞争之间的主要区别是（）A．⼚商的⼴告开⽀不同B．⾮价格竞争的数量不同C．⼚商之间相互影响的程度不同D．以上都不对10、在拐折需求曲线模型中，拐点左右两边的需求弹性是（）A．左边弹性⼤，右边弹性⼩ B．左边弹性⼩，右边弹性⼤C．左右两边弹性⼀样⼤ D．以上都不对⼆、填空题1、如果⼀个垄断⼚商⾯对的需求弹性很⼩，他将______价格，以增加收益。
西方经济学(第五版)课后习题答案详解
西方经济学（微观部分+宏观部分）第五版课后习题答案主编：高鸿业目录第一章引论02第二章需求、供给和均衡价格02第三章效用论14 第四章生产论16 第五章成本论36 第六章完全竞争市场45 第七章不完全竞争市场55 第八章生产要素价格的决定65第九章一般均衡和福利经济学69第十章博弈论初步75第十一章市场失灵和微观经济政策80 第十二章国民收入核算83 第十三章简单国民收入决定理论85 第十四章产品市场和货币市场的一般均衡92 第十五章宏观经济政策分析95 第十六章宏观经济政策实践106 第十七章总需求一总供给模型110第十八章失业与通货膨胀115 第十九章开放经济下的短期经济模型119第二十章经济增长和经济周期理论122第二十一章宏观经济学的微观基础127 第二十二章宏观经济学在目前的争论和共识134 第二十三章西方经济学与中国139第一章引论（略）第二章需求、供给和均衡价格1. 已知某一时期内某商品的需求函数为Q d＝50－5P，供给函数为Q s＝－10＋5P。
(1)求均衡价格P e和均衡数量Q e，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Q d＝60－5P。
求出相应的均衡价格P e和均衡数量Q e，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，使供给函数变为Q s＝－5＋5P。
求出相应的均衡价格P e和均衡数量Q e，并作出几何图形。
(4)利用(1)、(2)和(3)，说明静态分析和比较静态分析的联系和区别。
(5)利用(1)、(2)和(3)，说明需求变动和供给变动对均衡价格和均衡数量的影响。
解答：(1)将需求函数Q d＝50－5P和供给函数Q s＝－10＋5P代入均衡条件Q d＝Q s，有50－5P＝－10＋5P得P e＝6将均衡价格P e＝6代入需求函数Q d＝50－5P，得Q e＝50－5×6＝20或者，将均衡价格P e＝6代入供给函数Q s＝－10＋5P，得Q e＝－10＋5×6＝20所以，均衡价格和均衡数量分别为P e＝6，Q e＝20。
西方经济学习题第7章
第七章一般均衡与福利理论（本章不作为考试内容，仅用于练习）一、单项选择题1．一般均衡的代表人物是（）A．瓦尔拉斯B．马歇尔C．帕累托D．埃奇沃斯2．一般均衡的目标是（）A．企业利润最大B．实现公平C．经济效率最优D．充分就业3．在评价经济效率时，新福利经济学采用的是（）A．帕累托最优标准B．庇古最优标准C．公平标准D．就业标准4．按照帕累托的理论，消费者福利最优化的分析，利用了（）A．等成本线B．无差异曲线C．生产可能线D．菲利普斯曲线6.消费者的各自商品组合达到这样一种状态，任何一种改变在不使另一个人的境况变坏的条件下，都不可能使任何一个人的境况变好。
这是（）A．消费者福利最优的条件。
B．生产者福利最优化的条件C．社会福利的最优的条件D．产出的最优的条件7.运用数理逻辑证明，在一般情况下，要从已知的各种个人偏好顺序中推导出统一的社会偏好顺序是不可能的。
这个定理被称为（）A．科斯定理B．偏好次序定理C．阿罗不可能定理D．数理逻辑定理二、多项选择题１．把符合帕累托最优实现条件的切点连接起来的线，称为（）A．效率线B．效用可能性曲线C．交易契约曲线D．生产契约曲线E．边际技术替代率曲线2．在其他条件不变的情况下，社会可能生产的商品的最大组合的线叫（）A．生产可能性曲线B．交易契约曲线C．生产可能性边界D．其斜率称为边际转换率E．产品转换曲线三、判断题1．局部均衡的代表人物是帕累托。
2．一般均衡的目标是经济效率最优。
3．按照帕累托的理论，消费者福利最优化的分析，利用了生产可能线。
4. 按照帕累托的理论，将符合帕累托最优实现条件的切点连接起来的线，称为效率线。
四、概念联线1．局部均衡：一般是指单个市场或部分市场的供求与价格之间的关系或均衡状态。
2．一般均衡：是指在承认供求与市场上各种商品价格存在相互关系和相互影响条件下，所有市场上各种商品的价格与供求的关系或均衡状态。
3．帕累托改进：如果某一经济变动改善了一些人的状况，同时又不使另一些人蒙受损失，这个变动就增进了社会福利。
西方经济学 习题 高鸿业版 中国人民大学出版社
第七章不完全竞争市场一、选择题1、如果在需求曲线某一点上的需求的价格弹性ed=5，商品的价格P=6，则相应的边际收益MR为：（）A、7.5B、4.8C、1D、242 垄断竞争厂商所面对的需求曲线A ．是平行于横轴的直线B ．是垂直于横轴的直线C ．向右下方倾斜的D ．以上都正确3．一般情况下，在垄断厂商的长期均衡产量上有（）A．P>LAC；B．P<LAC；C．P等于最小的LAC；D．以上情况都可能存在。
4．弯折的需求曲线模型的假定有：（）A．行业内寡头厂商们提价时，其他寡头厂商都会仿效。
B．行业内某个寡头厂商提价时，其他寡头厂商都会仿效。
C．行业内某个寡头厂商降价时，其他寡头厂商都会仿效。
D．以上都对5．对垄断厂商来说（）。
A．提高价格一定能够增加收益；B．降低价格一定会减少收益C．提高价格未必能增加收益，降低价格未必减少收益；D．以上都不对。
6．垄断厂商的总收益与价格同时下降的前提条件是（）。
A．Ed＞1；B．Ed ＜1；C．Ed＝1；D．Ed ＝0。
7．一垄断者如果有一线性需求函数，总收益最大时（）。
A．边际收益为正值且递增；B．边际收益为正值且递减；C．边际收益为负值；D．边际收益为零。
8．垄断厂商的产品需求弹性为1时（）。
A．总收益最小；B．总收益最大；C．总收益递增；D．总收益递减。
9．如果在需求曲线上有一点，Ed＝2，P＝20元，则MR为（）。
A．30元；B．10元；C．60元；D．—10元。
10．当垄断市场的需求富有弹性时，MR为（）。
A．正；B．负；C．0；D．1。
11．如果市场价格超过平均成本，边际收益大于边际成本，垄断厂商多卖1单位时（）。
A．对总利润没有影响，但会缩小边际收益和边际成本之间的差额；B．总利润会减少；C．厂商总收益会减少，其数额等于P－AC；D．总利润会增加，其数额为MR－MC，并缩小边际收益和边际成本之间的差额。
12．完全垄断厂商的平均收益曲线为直线时，边际收益曲线也是直线。
西方经济学第六章第七章课后题(含答案)解析
完全竞争市场P172-1734、已知某完全竞争行业中的单个厂商的短期成本函数为STC=0.1Q3-2Q2+15Q+10。
试求：（1）当市场上产品的价格为P=55时，厂商的短期均衡产量和利润；（2）当市场价格下降为多少时，厂商必须停产？（3）厂商的短期供给函数。
5、已知某完全竞争的成本不变行业中的单个厂商的长期总成本函数LTC=Q3-12Q2+40Q。
试求：（1）当市场商品价格为P=100时，厂商实现MR=LMC时的产量、平均成本和利润；（2）该行业长期均衡时的价格和单个厂商的产量；（3）当市场的需求函数为Q=660-15P时，行业长期均衡时的厂商数量。
9、已知完全竞争市场上单个厂商的长期成本函数为LTC=Q3-20Q2+200Q ，市场的产品价格为P=600。
求：（1）该厂商实现利润最大化时的产量、平均成本和利润各是多少？（2）该行业是否处于长期均衡？为什么？（3）该行业处于长期均衡时每个厂商的产量、平均成本和利润各为多少？（4）判断（1）中的厂商是处于规模经济阶段，还是处于规模不经济阶段？不完全竞争市场P2066.已知某垄断厂商利用一个工厂生产一种产品，其产品在两个分割的市场上出售，他的成本函数为Q Q TC 402+=，两个市场的需求函数分别为111.012P Q -=，224.020P Q -=。
求：(1)当该厂商实行三级价格歧视时，他追求利润最大化前提下的两市场各自的销售量、价格以及厂商的总利润。
(2)当该厂商在两个市场实行统一的价格时，他追求利润最大化前提下的销售量、价格以及厂商的总利润。
(3)比较（1）和（2）的结果。
10.某寡头行业有两个厂商，厂商1的成本函数为118Q C =，厂商2的成本函数为2220.8Q C =，该市场的需求函数为P ＝152－0.6Q 。
求：该寡头市场的古诺模型解。
(保留一位小数。
)11.某寡头行业有两个厂商，厂商1为领导者，其成本函数为C 1＝13.8Q 1，厂商2为追随者，其成本函数为C 2＝20Q 2，该市场的需求函数为P ＝100－0.4Q 。
高鸿业,微观经济学,第七版,课后答案,西方经济学18第七章不完全竞争的市场
第七章不完全竞争的市场第一部分 教材配套习题本习题详解一、简答题1．根据图20中线性需求曲线d 和相应的边际收益曲线MR ，试求： (1)A 点所对应的MR 值；(2)B 点所对应的MR 值。
图7-1答：由图７—１可知需求曲线ｄ为P=－351+Q , TR(Q)=P ·Q= －Q Q 3512+, 所以MR=TR ′ (Q)= －352+Q(1)A 点(Q=5，P=2) 的MR 值为:MR (5)= －352+Q =1； (2)B 点(Q=10，P=1) 的MR 值为: MR (10)= －352+Q =－1 本题也可以用MR=P(1--dE 1)求得： E A =2，P A =2，则MR=P(1--d E 1)=2x （1- 12）=1 E B =12，P B =1，则MR=P(1--d E 1)=1x （1- 10.5）=-1２．图７—２是某垄断厂商的长期成本曲线、需求曲线和收益曲线。
试在图中标出：（１）长期均衡点及相应的均衡价格和均衡产量；（２）长期均衡时代表最优生产规模的ＳＡＣ曲线和ＳＭＣ 曲线；（３）长期均衡时的利润量。
图７—２解答：（１）如图７—３所示，长期均衡点为Ｅ点，因为在Ｅ点有ＭＲ＝ＬＭＣ。
由Ｅ点出发，均衡价格为Ｐ，均衡数量为Ｑ０。
０（２）长期均衡时代表最优生产规模的ＳＡＣ曲线和ＳＭＣ曲线如图７—３所示。
在Ｑ０的产量上，ＳＡＣ曲线和ＬＡＣ曲线相切；ＳＭＣ曲线和ＬＭＣ曲线相交，且同时与ＭＲ曲线相交。
（３）长期均衡时的利润量由图７—３中阴影部分的面积表示，即:π＝[AR(Q0)－SAC(Q0)]·Q。
图７—３3.为什么垄断厂商实现MR=MC的利润最大化均衡时,总有P>MC? 你是如何理解这种状态的?解答：在完全竞争市场条件下，由于厂商的MR＝P，所以完全竞争厂商利润最大化的原则MR＝MC可以改写为P＝MC。
这就是说，完全竞争厂商的产品价格等于产品的边际成本。
西财《经济学基础》教学资料 课后习题答案 第七章
第七章分配理论思考题1．名词解释：源泉价格边际收益产品边际要素成本边际产品价值准租金经济租金洛伦兹曲线基尼系数源泉价格：源泉价格是指买卖生产要素的服务“载体”（或称源泉）的价格。
边际收益产品：服务价格是指买卖要素提供的服务本身的价格。
边际要素成本：厂商在决定使用多少生产要素投入时，还必须比较成本和收益，即追加一单位生产要素所获得的收益能否补偿他为使用该单位要素所需支付的成本。
这种增加一单位投入要素所增加的成本支出称为边际要素成本。
边际产品价值：对任何一个厂商来说，每增加一单位产品的销售所带来的边际收益始终不变且等于产品价格。
从而要素的边际收益产品就等于边际物质产品乘以该产品的价格，被称为要素的边际产品价值。
准租金:准租金是指对任何供给量暂时固定的（短期内相对固定）生产要素的支付。
经济租金:经济租金可以定义为生产要素所得到的收入超过其在其他场所可能得到的收入部分。
洛伦兹曲线:为了考察收入分配的平等程度，美国统计学家洛伦兹提出了著名的洛伦兹曲线。
他首先将一国总人口按收入由低到高排队，然后考虑一定累计人口比例所获得的收入累计比例，如从收入最低起累计20%人口获得的收入累计比例为3%，累计40%的人口获得的累计收入比例为7.5%，等等。
以人口累计比例为横轴，收入累计比例为纵轴，将以上累计百分比的对应关系描绘出来，就得到洛伦兹曲线。
基尼系数:意大利经济学家基尼以洛伦兹曲线为基础，提出了判断收入分配平等程度的指标——基尼系数。
在经济未充分发展的阶段，收入分配将随同经济发展而趋于不平等，因而基尼系数较大；其后，经历收入分配暂时无大变化的时期，到达经济充分发展阶段，收入分配将趋于平等，基尼系数将变小。
2．简述生产要素需求的特点。
生产要素需求不仅是一种派生需求，也是一种联合需求。
派生需求是指厂商购买生产要素并不是为了满足厂商本身的需要，而是要将生产要素投入到生产过程中，通过生产要素生产出满足消费者需要的产品和劳务，由此获取利润。
曼昆微观经济学课后练习英文答案(第七章)
rketsWHAT’S NEW IN THE SIXTH EDITION:There are no major changes to this chapter.LEARNING OBJECTIVES:By the end of this chapter, students should understand:the link between buyers’ willingness to pay for a good and the demand curve.how to define and measure consumer surplus.the link between sellers’ costs of producing a good and the supply curve.how to define and measure producer surplus.that the equilibrium of supply and demand maximizes total surplus in a market.CONTEXT AND PURPOSE:Chapter 7 is the first chapter in a three-chapter sequence on welfare economics and market efficiency. Chapter 7 employs the supply and demand model to develop consumer surplus and producer surplus as a measure of welfare and market efficiency. These concepts are then utilized in Chapters 8 and 9 to determine the7CONSUMERS, PRODUCERS, AND THE EFFICIENCY OF MARKETSwinners and losers from taxation and restrictions on international trade.The purpose of Chapter 7 is to develop welfare economics—the study of how the allocation of resources affects economic well-being. Chapters 4 through 6 employed supply and demand in a positive framework, which focused on the question, “What is the equilibrium price and quantity in a market?” This chapter now addresses the normative question, “Is the equ ilibrium price and quantity in a market the best possible solution to the resource allocation problem, or is it simply the price and quantity that balance supply and demand?” Students will discover that under most circumstances the equilibrium price and quantity is also the one that maximizes welfare.KEY POINTS:Consumer surplus equals buyers’ willingness to pay for a good minus the amount they actually pay for it, and it measures the benefit buyers get from participating in a market. Consumer surplus can be computed by finding the area below the demand curve and above the price.Producer surplus equals the amount sellers receive for their goods minus their costs of production, and it measures the benefit sellers get from participating in a market. Producer surplus can be computed by finding the area below the price and above the supply curve.An allocation of resources that maximizes the sum of consumer and producer surplus is said to be efficient. Policymakers are often concerned with the efficiency, as well as the equality, of economic outcomes.The equilibrium of supply and demand maximizes the sum of consumer and producer surplus. That is, the invisible hand of the marketplace leads buyers and sellers to allocate resources efficiently.Markets do not allocate resources efficiently in the presence of market failures such as market power or externalities.CHAPTER OUTLINE:I. Definition of welfare economics: the study of how the allocation of resources affects economic well-being.II. Consumer SurplusStudents often are confused by the use of the word “welfare.” Remind them that we are talking about social well-being and not public assistance.A. Willingness to Pay1. Definition of willingness to pay: the maximum amount that abuyer will pay for a good.2. Example: You are auctioning a mint-condition recording ofElvis Presley’s first album. Four buyers show up. Theirwillingness to pay is as follows:If the bidding goes to slightly higher than $80,all buyers drop out except for John. Because Johnis willing to pay more than he has to for the album,he derives some benefit from participating in themarket.3. Definition of consumer surplus: the amount a buyer iswilling to pay for a good minus the amount the buyeractually pays for it.4. Note that if you had more than one copy of the album, theover $70 in the case of two albums) and both John and Paul would gain consumer surplus.B. Using the Demand Curve to Measure Consumer Surplus1. We can use the information on willingness to pay to derivea demand curve for the rare Elvis Presley album.2. At any given quantity, the price given by the demand curvereflects the willingness to pay of the marginal buyer.Because the demand curve shows the buyers’ willingness to pay, we can use the demand curve to measure consumersurplus.Figure 23. Consumer surplus can be measured as the area below thedemand curve and above the price.C. How a Lower Price Raises Consumer SurplusFigure 31. As price falls, consumer surplus increases for two reasons.a. Those already buying the product will receive additionalconsumer surplus because they are paying less for theproduct than before (area A on the graph).b. Because the price is now lower, some new buyers willenter the market and receive consumer surplus on theseadditional units of output purchased (area B on thegraph).D. What Does Consumer Surplus Measure?1. Remember that consumer surplus is the difference between the amount that buyers are willing to pay for a good and the price that they actually pay.2. Thus, it measures the benefit that consumers receive from the good as the buyers themselves perceive it.III. Producer SurplusA. Cost and the Willingness to Sell1. Definition of cost: the value of everything a seller mustgive up to produce a good .ALTERNATIVE CLASSROOM EXAMPLE:Review the material on price ceilings from Chapter 6. Redraw the market for two-bedroom apartments in your town. Draw in a price ceiling below the equilibrium price.Then go through:▪ consumer surplus before the price ceiling is put into place. ▪ consumer surplus after the price ceiling is put into place.You will need to take some time to explain the relationship between the producers’ willingness to sell and the cost of producing the good. The relationship between cost and the supply curve is not as apparent as the relationship between the demand curve and willingness to pay.It is important to stress that consumer surplus is measured in monetary terms. Consumer surplus gives us a way to place a monetary cost on inefficient market outcomes (due to government involvement or market failure).2. Example: You want to hire someone to paint your house. Youaccept bids for the work from four sellers. Each painter is willing to work if the price you will pay exceeds heropportunity cost. (Note that this opportunity cost thusrepresents willingness to sell.) The costs are:3. Bidding will stop when the price gets to be slightly below$600. All sellers will drop out except for Grandma. Because Grandma receives more than she would require to paint the house, she derives some benefit from producing in themarket.4. Definition of producer surplus: the amount a seller is paidfor a good minus the seller’s cost of providing it.5. Note that if you had more than one house to paint, theprice in the auction would end up being higher (a little under $800 in the case of two houses) and both Grandma and Georgia would gain producer surplus.B. Using the Supply Curve to Measure Producer Surplus1. We can use the information on cost (willingness to sell) toderive a supply curve for house painting services.Price Sellers QuantitySupplied$900 ormoreMary, Frida,Georgia, Grandma4$800 to$900Frida, Georgia,Grandma3$600 to$800Georgia, Grandma2$500 to$600Grandma1less than$500None02. At any given quantity, the price given by the supply curverepresents the cost of the marginal seller. Because thesupply curve shows the sellers’ cost (willingness to sell), we can use the supply curve to measure producer surplus. Figure 4Figure 53. Producer surplus can be measured as the area above thesupply curve and below the price.C. How a Higher Price Raises Producer Surplus1. As price rises, producer surplus increases for two reasons.a. Those already selling the product will receiveadditional producer surplus because they are receivingmore for the product than before (area C on the graph).b. Because the price is now higher, some new sellers willenter the market and receive producer surplus on theseadditional units of output sold (area D on the graph).D. Producer surplus is used to measure the economic well-beingof producers, much like consumer surplus is used to measure the economic well-being of consumers.Figure 6ALTERNATIVE CLASSROOM EXAMPLE:Review the material on price floors from Chapter 6. Redraw the market for anagricultural product such as corn. Draw in a price support above the equilibriumprice.Then go through:▪ producer surplus before the price support is put in place.▪ producer surplus after the price support is put in place.IV. Market EfficiencyA. The Benevolent Social Planner1. The economic well-being of everyone in society can bemeasured by total surplus, which is the sum of consumersurplus and producer surplus:Total Surplus = Consumer Surplus + ProducerSurplusTotal Surplus = (Value to Buyers – AmountPaid by Buyers) +(Amount Received by Sellers – Cost toSellers)Because the Amount Paid by Buyers = AmountReceived bySellers:2. Definition of efficiency: the property of a resource allocation of maximizing the total surplus received by all members of society .3. Definition of equality: the property of distributingeconomic prosperity uniformly the members of society .Total Surplus = Value to Buyers Cost to SellersNow might be a good time to point out that many government policies involve a trade-off between efficiency and equity. When you evaluate government policies, like price ceilings or floors, you can explain them in terms of equity and efficiency.Pretty Woman, Chapter 6. Vivien (Julia Roberts) and Edward (Richard Gere) negotiate a price. Afterward, Vivien reveals she would have accepted a lower price, while Edward admits he would have paid more. If you have done a good job of introducing consumer and producer surplus, you will see the light bulbs go off above your students’ heads as they watch this clip.B. Evaluating the Market EquilibriumFigure 71. At the market equilibrium price:a. Buyers who value the product more than the equilibriumprice will purchase the product; those who do not, willnot purchase the product. In other words, the freemarket allocates the supply of a good to the buyers whovalue it most highly, as measured by their willingnessto pay.b. Sellers whose costs are lower than the equilibrium pricewill produce the product; those whose costs are higher,will not produce the product. In other words, the freemarket allocates the demand for goods to the sellers whocan produce it at the lowest cost.2. Total surplus is maximized at the market equilibrium.Figure 8a. At any quantity of output smaller than the equilibriumquantity, the value of the product to the marginal buyer is greater than the cost to the marginal seller so total surplus would rise if output increases.b. At any quantity of output greater than the equilibriumquantity, the value of the product to the marginal buyer is less than the cost to the marginal seller so totalsurplus would rise if output decreases.3. Note that this is one of the reasons that economistsbelieve Principle #6: Markets are usually a good way toorganize economic activity.C. In the News: Ticket Scalping1. Ticket scalping is an example of how markets work toachieve an efficient outcome.2. This article from The Boston Globe describes economist ChipCase’s experience with ticket scalping.It would be a good idea to remind students that there are circumstances when the market process does not lead to the most efficient outcome. Examples include situations such as when a firm (or buyer) has market power over price or when there are externalities present. These situations will be discussed in later chapters.D. Case Study: Should There Be a Market in Organs?1. As a matter of public policy, people are not allowed tosell their organs.a. In essence, this means that there is a price ceiling onorgans of $0.b. This has led to a shortage of organs.2. The creation of a market for organs would lead to a moreefficient allocation of resources, but critics worry aboutthe equity of a market system for organs.V. Market Efficiency and Market FailureA. To conclude that markets are efficient, we made severalassumptions about how markets worked.1. Perfectly competitive markets.2. No externalities.B. When these assumptions do not hold, the market equilibriummay not be efficient.C. When markets fail, public policy can potentially remedy thesituation.SOLUTIONS TO TEXT PROBLEMS:Quick Quizzes1. Figure 1 shows the demand curve for turkey. The price ofturkey is P1 and the consumer surplus that results fromthat price is denoted CS. Consumer surplus is the amount abuyer is willing to pay for a good minus the amount thebuyer actually pays for it. It measures the benefit to buyers of participating in a market.Figure 1 Figure 22. Figure 2 shows the supply curve for turkey. The price ofturkey is P1 and the producer surplus that results from that price is denoted PS. Producer surplus is the amount sellers are paid for a good minus the sellers’ cost of providing it (measured by the supply curve). It measures the benefit to sellers of participating in a market.Figure 33. Figure 3 shows the supply and demand for turkey. The priceof turkey is P1, consumer surplus is CS, and producersurplus is PS. Producing more turkeys than the equilibriumquantity would lower total surplus because the value to themarginal buyer would be lower than the cost to the marginalseller on those additional units.Questions for Review1. The price a buyer is willing to pay, consumer surplus, andthe demand curve are all closely related. The height of thedemand curve represents the willingness to pay of thebuyers. Consumer surplus is the area below the demand curveand above the price, which equals the price that each buyeris willing to pay minus the price actually paid.2. Sellers' costs, producer surplus, and the supply curve areall closely related. The height of the supply curverepresents the costs of the sellers. Producer surplus isthe area below the price and above the supply curve, whichequals the price received minus each seller's costs ofproducing the good.Figure 43. Figure 4 shows producer and consumer surplus in a supply-and-demand diagram.4. An allocation of resources is efficient if it maximizestotal surplus, the sum of consumer surplus and producersurplus. But efficiency may not be the only goal ofeconomic policymakers; they may also be concerned aboutequity the fairness of the distribution of well-being.5. The invisible hand of the marketplace guides the self-interest of buyers and sellers into promoting generaleconomic well-being. Despite decentralized decision makingand self-interested decision makers, free markets oftenlead to an efficient outcome.6. Two types of market failure are market power andexternalities. Market power may cause market outcomes to beinefficient because firms may cause price and quantity todiffer from the levels they would be under perfectcompetition, which keeps total surplus from being maximized.Externalities are side effects that are not taken intoaccount by buyers and sellers. As a result, the free marketdoes not maximize total surplus.Problems and Applications1. a. Consumer surplus is equal to willingness to pay minusthe price paid. Therefore, Melissa’s willingness to paymust be $200 ($120 + $80).b. Her consumer surplus at a price of $90 would be $200 −$90 = $110.c. If the price of an iPod was $250, Melissa would not havepurchased one because the price is greater than herwillingness to pay. Therefore, she would receive noconsumer surplus.2. If an early freeze in California sours the lemon crop, thesupply curve for lemons shifts to the left, as shown inFigure 5. The result is a rise in the price of lemons and adecline in consumer surplus from A + B + C to just A. Soconsumer surplus declines by the amount B + C.Figure 5 Figure 6In the market for lemonade, the higher cost of lemonsreduces the supply of lemonade, as shown in Figure 6. Theresult is a rise in the price of lemonade and a decline inconsumer surplus from D + E + F to just D, a loss of E + F.Note that an event that affects consumer surplus in onemarket often has effects on consumer surplus in othermarkets.3. A rise in the demand for French bread leads to an increasein producer surplus in the market for French bread, asshown in Figure 7. The shift of the demand curve leads to an increased price, which increases producer surplus from area A to area A + B + C.Figure 7The increased quantity of French bread being sold increases the demand for flour, as shown in Figure 8. As a result, the price of flour rises, increasing producer surplus from area D to D + E + F. Note that an event that affectsproducer surplus in one market leads to effects on producer surplus in related markets.Figure 84. a. Bert’s demand schedule is:Price QuantityDemandedMore than$7$5 to $71$3 to $52$1 to $33$1 or less4Bert’s demand curve is shown in Figure 9.Figure 9b. When the price of a bottle of water is $4, Bert buys twobottles of water. His consumer surplus is shown as areaA in the figure. He values his first bottle of water at$7, but pays only $4 for it, so has consumer surplus of $3. He values his second bottle of water at $5, but pays only $4 for it, so has consumer surplus of $1. ThusBert’s total consumer surplus is $3 + $1 = $4, which is the area of A in the figure.c. When the price of a bottle of water falls from $4 to $2,Bert buys three bottles of water, an increase of one.His consumer surplus consists of both areas A and B in the figure, an increase in the amount of area B. He gets consumer surplus of $5 from the first bottle ($7 value minus $2 price), $3 from the second bottle ($5 valueminus $2 price), and $1 from the third bottle ($3 value minus $2 price), for a total consumer surplus of $9.Thus consumer surplus rises by $5 (which is the size of area B) when the price of a bottle of water falls from $4 to $2.5. a. Ernie’s supply schedule for water is:Price Quantity SuppliedMore than$74$5 to $73$3 to $52$1 to $31Less than$1Ernie’s sup ply curve is shown in Figure 10.Figure 10b. When the price of a bottle of water is $4, Ernie sellstwo bottles of water. His producer surplus is shown as area A in the figure. He receives $4 for his firstbottle of water, but it costs only $1 to produce, soErnie has producer surplus of $3. He also receives $4 for his second bottle of water, which costs $3 toproduce, so he has producer surplus of $1. Thus Ernie’s total producer surplus is $3 + $1 = $4, which is thearea of A in the figure.c. When the price of a bottle of water rises from $4 to $6,Ernie sells three bottles of water, an increase of one.His producer surplus consists of both areas A and B inthe figure, an increase by the amount of area B. He gets producer surplus of $5 from the first bottle ($6 priceminus $1 cost), $3 from the second bottle ($6 priceminus $3 cost), and $1 from the third bottle ($6 priceminus $5 price), for a total producer surplus of $9.Thus producer surplus rises by $5 (which is the size of area B) when the price of a bottle of water rises from$4 to $6.6. a. From Ernie’s supply schedule and Bert’s demandschedule, the quantity demanded and supplied are:Only a price of $4 brings supply and demand intoequilibrium, with an equilibrium quantity of two.b. At a price of $4, consumer surplus is $4 and producersurplus is $4, as shown in Problems 3 and 4 above. Total surplus is $4 + $4 = $8.c. If Ernie produced one less bottle, his producer surpluswould decline to $3, as shown in Problem 4 above. IfBert consumed one less bottle, his consumer surpluswould decline to $3, as shown in Problem 3 above. Sototal surplus would decline to $3 + $3 = $6.d. If Ernie produced one additional bottle of water, hiscost would be $5, but the price is only $4, so hisproducer surplus would decline by $1. If Bert consumedone additional bottle of water, his value would be $3,but the price is $4, so his consumer surplus woulddecline by $1. So total surplus declines by $1 + $1 = $2.7. a. The effect of falling production costs in the market forstereos results in a shift to the right in the supplycurve, as shown in Figure 11. As a result, theequilibrium price of stereos declines and theequilibrium quantity increases.Figure 11b. The decline in the price of stereos increases consumersurplus from area A to A + B + C + D, an increase in the amount B + C + D. Prior to the shift in supply, producer surplus was areas B + E (the area above the supply curve and below the price). After the shift in supply,producer surplus is areas E + F + G. So producer surplus changes by the amount F + G – B, which may be positiveor negative. The increase in quantity increases producer surplus, while the decline in the price reduces producer surplus. Because consumer surplus rises by B + C + D andproducer surplus rises by F + G – B, total surplusrises by C + D + F + G.c. If the supply of stereos is very elastic, then the shiftof the supply curve benefits consumers most. To take the most dramatic case, suppose the supply curve werehorizontal, as shown in Figure 12. Then there is noproducer surplus at all. Consumers capture all thebenefits of falling production costs, with consumersurplus rising from area A to area A + B.Figure 128. Figure 13 shows supply and demand curves for haircuts.Supply equals demand at a quantity of three haircuts and a price between $4 and $5. Firms A, C, and D should cut the hair of Ellen, Jerry, and Phil. Oprah’s willingness to pay is t oo low and firm B’s costs are too high, so they do not participate. The maximum total surplus is the area between the demand and supply curves, which totals $11 ($8 value minus $2 cost for the first haircut, plus $7 value minus $3cost for the second, plus $5 value minus $4 cost for the third).Figure 139. a. The effect of falling production costs in the market forcomputers results in a shift to the right in the supply curve, as shown in Figure 14. As a result, theequilibrium price of computers declines and theequilibrium quantity increases. The decline in the price of computers increases consumer surplus from area A to A + B + C + D, an increase in the amount B + C + D.Figure 14 Figure 15Prior to the shift in supply, producer surplus was areasB + E (the area above the supply curve and below theprice). After the shift in supply, producer surplus isareas E + F + G. So producer surplus changes by theamount F + G – B, which may be positive or negative.The increase in quantity increases producer surplus,while the decline in the price reduces producer surplus.Because consumer surplus rises by B + C + D and producersurplus rises by F + G – B, total surplus rises by C +D + F + G.b. Because typewriters are substitutes for computers, thedecline in the price of computers means that peoplesubstitute computers for typewriters, shifting thedemand for typewriters to the left, as shown in Figure15. The result is a decline in both the equilibriumprice and equilibrium quantity of typewriters. Consumersurplus in the typewriter market changes from area A + Bto A + C, a net change of C – B. Producer surpluschanges from area C + D + E to area E, a net loss of C +D. Typewriter producers are sad about technologicaladvances in computers because their producer surplusdeclines.c. Because software and computers are complements, thedecline in the price and increase in the quantity ofcomputers means that the demand for software increases,shifting the demand for software to the right, as shownin Figure 16. The result is an increase in both theprice and quantity of software. Consumer surplus in thesoftware market changes from B + C to A + B, a netchange of A – C. Producer surplus changes from E to C +D + E, an increase of C + D, so software producersshould be happy about the technological progress incomputers.Figure 16d. Yes, this analysis helps explain why Bill Gates is onethe world’s richest people, because his companyproduces a lot of software that is a complement withcomputers and there has been tremendous technologicaladvance in computers.10. a. With Provider A, the cost of an extra minute is $0.With Provider B, the cost of an extra minute is $1.b. With Provider A, my friend will purchase 150 minutes [=150 – (50)(0)]. With Provider B, my friend wouldpurchase 100 minutes [= 150 – (50)(1)].c. With Provider A, he would pay $120. The cost would be $100 with Provider B.Figure 17d. Figure 17 shows the friend’s demand. With Provider A,he buys 150 minutes and his consumer surplus is equal to(1/2)(3)(150) – 120 = 105. With Provider B, hisconsumer surplus is equal to (1/2)(2)(100) = 100.e. I would recommend Provider A because he receives greater consumer surplus.11. a. Figure 18 illustrates the demand for medical care.If each procedure has a price of $100, quantity demandedwill be Q1 procedures.曼昆微观经济学课后练习英文答案(第七章)Figure 18b. If consumers pay only $20 per procedure, the quantitydemanded will be Q2 procedures. Because the cost tosociety is $100, the number of procedures performed istoo large to maximize total surplus. The quantity thatmaximizes total surplus is Q1 procedures, which is lessthan Q2.c. The use of medical care is excessive in the sense thatconsumers get procedures whose value is less than thecost of producing them. As a result, the economy’stotal surplus is reduced.d. To prevent this excessive use, the consumer must bearthe marginal cost of the procedure. But this wouldrequire eliminating insurance. Another possibility wouldbe that the insurance company, which pays most of themarginal cost of the procedure ($80, in this case) coulddecide whether the procedure should be performed. Butthe insurance company does not get the benefits of theprocedure, so its decisions may not reflect the value tothe consumer.151 / 31© 2012 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.。
2019年西方经济学第7章测验题答案
题目信息文本一、填空题题目1未回答满分0.50标记题目题干市场结构是指市场的程度。
选择一项：a. 竞争b. 垄断与竞争反馈提示：各个市场的竞争与垄断程度不同形成了不同的市场结构。
不同的企业处于不同的市场，其竞争目标与手段都不同。
正确答案是：垄断与竞争题目2未回答满分0.50标记题目题干产品差别是指产品在质量、牌号、形式、包装等方面的差别。
选择一项：a. 不同b. 同一种反馈提示：一种产品不仅要满足人们的实际需要，还要满足人们的心理需要。
每个人由于收入水平、社会地位、文化教育、宗教信仰、历史传统不同，偏好也不同。
他们对同一种产品的细微差别都有一定要求。
产品差别正是为了满足消费者的不同偏好。
每种有差别的产品都以自己的某些特色吸引消费者。
这样，有特色的产品就在喜爱这一特色的消费者中形成了自己的垄断地位。
正在这种意义上，经济学家认为，产品差别引起垄断，产品差别越大，垄断程度越高。
正确答案是：同一种题目3未回答满分0.50标记题目题干根据行业的市场集中程度、行业的进入限制和产品差别，可以把市场分为、垄断、垄断竞争、寡头四种类型。
选择一项：a. 不完全竞争b. 完全竞争反馈提示：完全竞争、垄断、垄断竞争、寡头是市场的四种基本类型，还有些市场介于两种市场结构之间。
不完全竞争是相对于完全竞争而言的，它是指或多或少带有一定垄断因素的市场类型，主要包括垄断、垄断竞争、寡头。
正确答案是：完全竞争题目4未回答满分0.50标记题目题干垄断竞争市场与完全竞争市场的相同之处是市场集中率低，而且无进入限制，但关键差别是完全竞争产品差别，而垄断产品差别。
选择一项：a. 有无b. 无有反馈提示：划分市场结构的标准是市场集中程度、进入限制与产品差别。
垄断竞争是既有垄断又有竞争，垄断与竞争相结合的市场，产品差别是产生垄断的重要条件之一。
完全竞争是一种竞争不受任何阻碍和干扰的市场结构，进入无限制和产品无差别使这种市场上不会出现垄断。
正确答案是：无有题目5未回答满分0.50标记题目题干形成寡头市场的关键是。
高鸿业,微观经济学,第七版,课后答案,西方经济学18第七章不完全竞争的市场
第七章不完全竞争的市场第一部分 教材配套习题本习题详解一、简答题1．根据图20中线性需求曲线d 和相应的边际收益曲线MR ，试求： (1)A 点所对应的MR 值；(2)B 点所对应的MR 值。
图7-1答：由图７—１可知需求曲线ｄ为P=－351+Q , TR(Q)=P ·Q= －Q Q 3512+, 所以MR=TR ′ (Q)= －352+Q(1)A 点(Q=5，P=2) 的MR 值为:MR (5)= －352+Q =1； (2)B 点(Q=10，P=1) 的MR 值为: MR (10)= －352+Q =－1 本题也可以用MR=P(1--dE 1)求得： E A =2，P A =2，则MR=P(1--d E 1)=2x （1- 12）=1 E B =12，P B =1，则MR=P(1--d E 1)=1x （1- 10.5）=-1２．图７—２是某垄断厂商的长期成本曲线、需求曲线和收益曲线。
试在图中标出：（１）长期均衡点及相应的均衡价格和均衡产量；（２）长期均衡时代表最优生产规模的ＳＡＣ曲线和ＳＭＣ曲线；（３）长期均衡时的利润量。
图７—２解答：（１）如图７—３所示，长期均衡点为Ｅ点，因为在Ｅ点有ＭＲ＝ＬＭＣ。
由Ｅ点出发，均衡价格为Ｐ，均衡数量为Ｑ０。
０（２）长期均衡时代表最优生产规模的ＳＡＣ曲线和ＳＭＣ曲线如图７—３所示。
在Ｑ０的产量上，ＳＡＣ曲线和ＬＡＣ曲线相切；ＳＭＣ曲线和ＬＭＣ曲线相交，且同时与ＭＲ曲线相交。
（３）长期均衡时的利润量由图７—３中阴影部分的面积表示，即:π＝[AR(Q0)－SAC(Q0)]·Q。
图７—３3.为什么垄断厂商实现MR=MC的利润最大化均衡时,总有P>MC? 你是如何理解这种状态的?解答：在完全竞争市场条件下，由于厂商的MR＝P，所以完全竞争厂商利润最大化的原则MR＝MC可以改写为P＝MC。
这就是说，完全竞争厂商的产品价格等于产品的边际成本。