微观经济学课后复习题参考答案4
微观经济学习题四答案
答案:1、D 2、D 3、B 4、D 5、B 6、C 7、A8、C 9、A 10、B 11、D 12、D 13、D1、已知某企业的生产函数为Q=L2/3K1/3,劳动的价格w=2,资本的价格r=1。
求:(1)当成本C=3000时,企业实现最大产量时的L、K和Q的均衡值。
(2)当产量Q=800时,企业实现最小成本时的L、K和C的均衡值。
解:(1)Q=L2/3K1/3,w=2,r=1,C=30002L+K=3 000 ①由MPL/w=MPk/r得2/3×L-1/3K1/3/2=1/3L2/3K-2/3得K=L ②由①②,得K=L=1000 Q=1000(2)Q=L2/3K1/3=800由MPL/w:MPK/r得K=L由①②,得K=L=800C=2L+K=24002、 2、企业以变动要素L生产产品X,短期生产函数为q=12L+6L2-0.1L3 (1)APL最大时,需雇用多少工人?(2)MPL最大时,需雇用多少工人?(3)APK最大时,需雇用多少工人?解:由q=12L+6L2-0.1L3得(1)(1)APL=q/L=12+6L-0.1L2APL'=6-0.2L=0,L=30(2)MPL=dq/dL=12+12L-0.3L2MPL'=12-0.6L=0L=20(3)根据题设,仅L为变动要素,因此K为固定值(设K=K0)。
要求APK最大,即求APK=q/K=(12L+6L2-0.1L3)/K=(12L+6L2-0.1L3)/K0最大。
AP΄K=(12+12L-0.3L2)/K0=0,即12+12L-0.3L2=0,解之得:L=20+2 L=20-2 (舍去),因此,AP K最大时,需雇用L=20+2 ≈41个工人。
3.某企业使用劳动L和资本K进行生产,长期生产函数为q=20L+65K-0.5L2-0.5K2,每期总成本TC=2200元,要素价格w=20元,r=50元。
求企业最大产量,以及L和K的投入量。
(完整版)微观经济学第4章生产论习题与答案
第4章生产论【练习及思考】参考答案要点1.填空题(1)总产量曲线、平均产量曲线和边际产量曲线都呈现出先上升,而后达到最大值以后,再呈现出下降的趋势。
其中,边际产量最先达到最大值,而后开始下降并与平均产量的最大值相交。
(2)边际产量的变化随着可变要素投入的增加一般经历两个阶段,即递增和递减两个阶段。
(3)按照生产过程中使用的生产要素的搭配情况可将那生产函数分为两种类型固定比例生产函数和可变比例生产函数。
2.判断题(下列判断正确的在括号内打√,不正确的打×)1)(√)在一种可变投入生产函数中,可变要素合理投入区域应在AP>MP>0的阶段。
2)(×)在一种可变投入生产函数中,可变要素合理投入区域应在MP>AP的第一阶段。
3)(√)生产理论中的短期是指未能调整全部生产要素的时期。
4)(×)AP曲线与MP曲线交于MP曲线的最高点。
5)(×)能提供相同效用的不同商品数量组合的点的连线即为等产量曲线。
6)(×)等产量曲线表示的是用同样数量劳动和资本生产不同的产量。
7)(√)当劳动的边际产量小于其平均产量时,平均产量肯定是下降的。
8)(×)边际产量递减,平均产量也递减。
9)(√)在生产的第Ⅱ阶段,AP是递减的。
3.选择题1)理性的生产者选择的生产区域应是(CD)。
A.MP>AP阶段B.MP下降阶段C.AP>MP>0阶段D.MP与AP相交之点起至MP与横轴交点止2)下列说法中正确的是(AC)。
A.只要总产量减少,边际产量一定为负B.只要MP减少,总产量一定减少C.MP曲线必定交于AP曲线的最高点D.只要MP减少,AP 也一定减少3)最优生产要素组合点上应该有(ABD)。
A.等产量曲线和等成本线相切B.MRTS LK=w/rC.dk/dl=w/rD.MP L/MP k=w/r4)等产量曲线上任意两点的产量肯定是(A )。
A.相等B.不等C.无关D.以上情况都存在5)若横轴代表劳动,纵轴表示资本,且劳动的价格为w,资本的价格为r,则等成本线的斜率为(C )。
西方经济学(微观经济学)课后练习答案第四章
习题一、名词解释生产函数边际产量边际报酬递减规律边际技术替代率递规律等产量线等成本线规模报酬扩展线二、选择题1、经济学中,短期是指()A、一年或一年以内的时期B、在这一时期内所有投入要素均是可以变动的C、在这一时期内所有投入要至少均是可以变动的。
D、在这时期内,生产者来不及调整全部生产要素的数量,至少有一种生产要素的数量是固定不变的。
2、对于一种可变要素投入的生产函数QfL,所表示的厂商要素投入的合理区域为(D)A、开始于AP的最大值,终止于TP的最大值B、开始于AP与MP相交处,终止于MP等于零C、是MP递减的一个阶段D、以上都对3、当MP L AP L时,我们是处于(A)A、对于L的Ⅰ阶段B、对K的Ⅲ阶段C、对于L的Ⅱ阶段D、以上都不是4、一条等成本线描述了()A、企业在不同产出价格下会生产的不同数量的产出B、投入要素价格变化时,同样的成本下两种投入要素的不同数量C、一定的支出水平下,企业能够买到的两种投入要素的不同组合D、企业能够用来生产一定数量产出的两种投入要素的不同组合5、当单个可变要素的投入量为最佳时,必然有:A.总产量达到最大B.边际产量达到最高C.平均产量大于或等于边际产量D.边际产量大于平均产量6、当平均产量递减时,边际产量是()A、递减B、为负C、为零D、以上三种可能都有7、以下有关生产要素最优组合,也即成本最小化原则的描述正确的一项是().A.MPL/r L=MPK/r KB.MRTS LK=r L/r KC.P MPr KKD.A和B均正确8、等产量曲线上各点代表的是()A.为生产同等产量而投入的要素价格是不变的B.为生产同等产量而投入的要素的各种组合比例是不能变化的C.投入要素的各种组合所能生产的产量都是相等的D.无论要素投入量是多少,产量是相等的9、如果厂商甲的劳动投入对资本的边际技术替代率为13,厂商乙的劳动投入对资本的边际技术替代率为23,那么(D)A.只有厂商甲的边际技术替代率是递减的B.只有厂商乙的边际技术替代率是递减的C.厂商甲的资本投入是厂商乙的两倍D.如果厂商甲用3单位的劳动与厂商乙交换2单位的资本,则厂商甲的产量将增加10、如果等成本曲线围绕它与纵轴的交点逆时针转动,那么将意味着(A)A.横轴表示的生产要素的价格下降B.纵轴表示的生产要素的价格上升C.横轴表示的生产要素的价格上升D.纵轴表示的生产要素的价格下降11、若等成本曲线在坐标平面上与等产量曲线相交,那么该交点表示的产量水平()A.应增加成本支出B.应减少成本支出C.不能增加成本支出D.不能减少成本支出12、在规模报酬不变的阶段,若劳动的使用量增加5%,而资本的使用量不变,则()A.产出增加5%B.产出减少5%C.产出的增加少于5%D.产出的增加大于5%13、规模报酬递减是在下述哪种情况下发生的()A、按比例连续增加各种生产要素B、不按比率连续增加各种生产要素C、连续地投入某种生产要素而保持其他生产要素不变D、上述都正确14、下列说法中正确的是(D)A、生产要素的边际替代率递减是规模报酬递减造成的B、边际收益递减是规模报酬递减规律造成的C、规模报酬递减是边际收益递减规律造成的D、生产要素的边际技术替代率递减是边际收益递减规律造成的15、当某厂商以最小成本生产出既定产量时(D)A、总收益为零B、获得最大利润C、没有获得最大利润D、无法确定是否获得了最大总利润三、判断题1、随着某种生产要素投入量的增加,边际产量和平均产量到一定程度将趋于下降,其中边际产量的下降一定先于平均产量。
微观经济学第四章习题答案完整版
微观经济学第四章习题答案HEN system office room 【HEN16H-HENS2AHENS8Q8-HENH1688】第四章生产论1. 下面(表4—1)是一张一种可变生产要素的短期生产函数的产量表:可变要素的数量可变要素的总产量可变要素的平均产量可变要素的边际产量122103244125606677080963(2)该生产函数是否表现出边际报酬递减如果是,是从第几单位的可变要素投入量开始的解答:(1)利用短期生产的总产量(TP)、平均产量(AP)和边际产量(MP)之间的关系,可以完成对该表的填空,其结果如表4—2所示:可变要素的数量可变要素的总产量可变要素的平均产量可变要素的边际产量1222212610324812448122456012126661167701048708\f(34)09637-7高点以后开始逐步下降的这样一种普遍的生产现象。
本题的生产函数表现出边际报酬递减的现象,具体地说,由表4—2可见,当可变要素的投入量从第4单位增加到第5单位时,该要素的边际产量由原来的24下降为12。
2. 用图说明短期生产函数Q=f(L,eq \o(K,\s\up6(-)))的TPL曲线、APL 曲线和MPL曲线的特征及其相互之间的关系。
解答:短期生产函数的TPL曲线、APL曲线和MPL曲线的综合图如图4—1所示。
图4—1由图4—1可见,在短期生产的边际报酬递减规律的作用下,MPL曲线呈现出先上升达到最高点A以后又下降的趋势。
从边际报酬递减规律决定的MPL曲线出发,可以方便地推导出TPL 曲线和APL曲线,并掌握它们各自的特征及相互之间的关系。
关于TPL 曲线。
由于MPL=eq \f(d TP L,d L),所以,当MP L>0时,TP L曲线是上升的;当MPL <0时,TPL曲线是下降的;而当MPL=0时,TPL曲线达最高点。
换言之,在L=L3时,MPL曲线达到零值的B点与TPL曲线达到最大值的B′点是相互对应的。
西方经济学(微观经济学)课后练习答案第四章
习 题一、名词解释生产函数 边际产量 边际报酬递减规律 边际技术替代率递规律 等产量线 等成本线 规模报酬 扩展线二、选择题1、经济学中,短期是指( )A 、一年或一年以内的时期B 、在这一时期内所有投入要素均是可以变动的C 、在这一时期内所有投入要至少均是可以变动的。
D 、在这时期内,生产者来不及调整全部生产要素的数量,至少有一种生产要素的数量是固定不变的。
2、对于一种可变要素投入的生产函数()Q f L =,所表示的厂商要素投入的合理区域为( D )A 、开始于AP 的最大值,终止于TP 的最大值B 、开始于AP 与MP 相交处,终止于MP 等于零C 、是MP 递减的一个阶段D 、以上都对3、当L L MP AP >时,我们是处于( A )A 、对于L 的Ⅰ阶段B 、对K 的Ⅲ阶段C 、对于L 的Ⅱ阶段D 、以上都不是4、一条等成本线描述了( )A 、企业在不同产出价格下会生产的不同数量的产出B 、投入要素价格变化时,同样的成本下两种投入要素的不同数量C 、一定的支出水平下,企业能够买到的两种投入要素的不同组合D 、企业能够用来生产一定数量产出的两种投入要素的不同组合5、当单个可变要素的投入量为最佳时,必然有:A. 总产量达到最大B. 边际产量达到最高C. 平均产量大于或等于边际产量D. 边际产量大于平均产量6、当平均产量递减时,边际产量是( )A 、递减B 、为负C 、为零D 、以上三种可能都有7、以下有关生产要素最优组合,也即成本最小化原则的描述正确的一项是(). A.MPL /r L =MPK /r KB.MRTS LK =r L /r KC.K P MP ⋅=r KD.A和B均正确8、等产量曲线上各点代表的是( )A.为生产同等产量而投入的要素价格是不变的B.为生产同等产量而投入的要素的各种组合比例是不能变化的C.投入要素的各种组合所能生产的产量都是相等的D.无论要素投入量是多少,产量是相等的9、如果厂商甲的劳动投入对资本的边际技术替代率为13,厂商乙的劳动投入对资本的边际技术替代率为23,那么(D )A.只有厂商甲的边际技术替代率是递减的B.只有厂商乙的边际技术替代率是递减的C.厂商甲的资本投入是厂商乙的两倍D.如果厂商甲用3单位的劳动与厂商乙交换2单位的资本,则厂商甲的产量将增加10、如果等成本曲线围绕它与纵轴的交点逆时针转动,那么将意味着(A )A.横轴表示的生产要素的价格下降B.纵轴表示的生产要素的价格上升C.横轴表示的生产要素的价格上升D.纵轴表示的生产要素的价格下降11、若等成本曲线在坐标平面上与等产量曲线相交,那么该交点表示的产量水平()A.应增加成本支出B.应减少成本支出C.不能增加成本支出D.不能减少成本支出12、在规模报酬不变的阶段,若劳动的使用量增加5%,而资本的使用量不变,则()A.产出增加5%B.产出减少5%C.产出的增加少于5%D.产出的增加大于5%13、规模报酬递减是在下述哪种情况下发生的()A、按比例连续增加各种生产要素B、不按比率连续增加各种生产要素C、连续地投入某种生产要素而保持其他生产要素不变D、上述都正确14、下列说法中正确的是(D )A、生产要素的边际替代率递减是规模报酬递减造成的B、边际收益递减是规模报酬递减规律造成的C、规模报酬递减是边际收益递减规律造成的D、生产要素的边际技术替代率递减是边际收益递减规律造成的15、当某厂商以最小成本生产出既定产量时(D )A、总收益为零B、获得最大利润C、没有获得最大利润D、无法确定是否获得了最大总利润三、判断题1、随着某种生产要素投入量的增加,边际产量和平均产量到一定程度将趋于下降,其中边际产量的下降一定先于平均产量。
最新微观经济学4章习题及答案
牛奶价格为10面包价格为2时,张某应增加面包的消费
问题2
得5分,满分5分
预算线的位置与斜率取决于
答案
所选答案:
D.
消费者收入和商品价格
正确答案:
D.
消费者收入和商品价格
问题3
得5分,满分5分
当X商品的价格下降时,替代效应为+5,收入效应为+3,则该商品是
答案
所选答案:
A.
正常商品
正确答案:
A.
正常商品
问题4
得5分,满分5分
下列选项中不是对消费者选择理论的批评的是
答案
所选答案:
C.
需求曲线不是向下倾斜的
正确答案:
C.
需求曲线不是向下倾斜的
问题5
得5分,满分5分
消费者的无差异曲线具有()的特点
答案
所选答案:
B.
斜率的绝对值递减
C.
任意两条无差异曲线都不相交
D.
位于右上方的无差异曲线具有较高的效用水平
答案
所选答案:
对
正确答案:
对
问题13
得5分,满分5分
序数效用论认为,商品效用的大小可以比较
答案
所选答案:
对
正确答案:
对
问题14
得5分,满分5分
关于消费者均衡点的下列说法正确的有
答案
所选答案:
A.
均衡点位于预算约束线上
C.
均衡点由预算线和无差异曲线的切点决定
正确答案:
A.
均衡点位于预算约束线上
C.
均衡点由预算线和无差异曲线的切点决定
微观经济学4章习题及答案
问题1
得5分,满分5分
(完整版)微观经济学复习题库及答案
(完整版)微观经济学复习题库及答案第⼀章1、微观经济学对个体经济单位的考察是在以下三个层次上逐步深⼊的:A、分析单个消费者和单个⽣产者的经济⾏为。
B、分析单个市场均衡价格的决定。
C、分析社会总供给和总需求决定的均衡价格。
D、分析所有单个市场均衡价格的同时决定。
2、经济学中假定的“经济⼈”是A、理性的⼈。
B、⾃利⾏为的⼈。
C、损⼈利已的⼈。
D、以最⼩的经济代价去获得最⼤经济利益的⼈。
3、居民是A、⽣产要素的供给者。
B、产品的供给者。
C、产品的购买者。
D、⽣产要素的购买者。
4、经济学包括的主要问题有A、⽣产什么和⽣产多少;B、如何⽣产;C、为谁⽣产;D、⽣产者选择利润最⼤化;E、消费者选择效⽤最⼤化。
本章答案:1、ABD2、ABD3、AC4、ABCDE第⼆章⼀.名词解释1. 需求消费者在⼀定时期内在各种可能的价格⽔平愿意⽽且能够购买的该商品的数量。
2. 供给⽣产者在⼀定时期内在各种价格⽔平下愿意并且能够提供出售的该种商品的数量。
3. 均衡价格⼀种商品的均衡价格是指该种商品的市场需求量和市场供给量相等时的价格。
4. 需求量的变动和需求的变动需求量的变动是指在其它条件不变时由某种商品的价格变动所应起的该商品需求数量的变动。
需求的变动是指在某商品价格不变的条件下,由于其它因素变动所引起的该商品需求数量的变动。
5. 供给量的变动和供给的变动供给量的变动是指在其它条件不变时由某种商品的价格变动所应起的该商品供给数量的变动。
供给的变动是指在某商品价格不变的条件下,由于其它因素变动所引起的该商品供给数量的变动。
6. 弹性当⼀个经济变量发⽣1%的变动时,由它引起的另⼀个经济变量变动的百分⽐。
7. 需求的价格弹性表⽰在⼀定时期内⼀种商品的需求量变动对于该商品的价格变动的反应程度。
或者说,表⽰在⼀定时期内当⼀种商品的价格变化百分之⼀时所引起的该商品的需求量变化的百分⽐。
8. 供给的价格弹性表⽰在⼀定时期内⼀种商品的供给量的变动对于该商品的价格的变动的反应程度。
微观经济学课后复习题及答案
A.人们决定多生孩子。
答:决定需求和供给的预期因素都受到影响。人们预期孩子多了,家庭开支会增大,家用旅行车的需求会减少。从供给角度来看,由于人口会增加,对家用旅行车的消费量也会增加,于是生产商会增加供给。
C.未来6个月的暖气用油或未来5年的暖气用油。
答:未来5年的暖气用油更富有弹性。因为无论对需求还是对供给来说,时期越长,就越富有弹性。
D.生啤酒或水。
答:生啤酒更富有弹性。因为Байду номын сангаас是生活必需品,价格因素的影响力不大,而生啤酒只是一种消遣的饮料,价格上升,人们对它的需求量就会下降。
2.假设公务乘客和度假乘客对从纽约到波士顿之间民航机票的需求如下:
公务乘客的需求价格弹性= =0.23
(ⅱ)中点:价格=225,数量=700
度假乘客的需求价格弹性= =1.29
B.为什么度假乘客与公务乘客的弹性不同?
答:对公务人员来说,时间成本较高,飞机是最快的交通工具,为了节省时间,即使机票价格升高,他们的最佳选择还可能是坐飞机,所以他们的机票需求价格弹性小。度假乘客则不同,他们是为了外出游玩,时间成本比较低。如果机票价格升高,为了节省度假成本,他们可以选择其他交通工具。因此,他们的需求价格弹性大。
5.6
2.5
4
120
30
600
5
3.3
5
140
20
700
5
5
6
150
10
800
5.3
10
7
155
5
微观经济学课件及课后答案4
3、已知生产函数Q=f(L, K)=2KL-0.5L2- 0.5K2, 假定厂商目前处于 短期生产,且K=10.
(1)写出在短期生产中该厂商关于劳动的总产量TPL函数、劳动的 平均APL函数和劳动的边际产量MPL函数。 (2)分别计算当劳动总产量TPL函数、劳动的平均APL函数和劳动 的边际产量MPL函数各自达到极大值时的厂商的劳动投入量。 解: (1) TPL =f(L, 10)= -0.5L2 +20L- 50
产的扩展线方程为K 3
L 3
,
即 2L
10 L1/ 3 K 1/ 3 3
PK K / PL
PK
5 L2/ 3 K 2/ 3 3
P, L
当PL=1,PK=1, Q=1000时,厂商长期生产的扩展线方程为2L=K.
厂商实现最小成本的要素投入组合满足下列方程组
所以 ,
2L K
Q
5L1/ 3 K 2/ 3
6、假设某厂商的短期生产函数为 Q 35L 8L2 L3 。 求:(1)该企业的平均产量函数和边际产量函数。 (2)如果企业使用的生产要素的数量 L=6,是否处于短期生产的合理区间? 为什么? 解:(1)平均产量函数 APL Q / L 35 8L L2 ,
边际产量函数 M PL d Q/ dL3 5 1 6 L 23 L (2)当 APL MPL 时,L=4(取正根);当 MPL=0 时,L=7(取正根)。 当企业使用的生产要素的数量 L=6,介于 4 与 7 之间,处于短期生产的合 理区间。
1000
L 100 3 2, K 200 3 2
(2)
Q KL,
KL
Q K
(K
L2 L)2
,
Q L
4微观经济学复习题及参考答案
Байду номын сангаас
[ D]
[ D ] [ D] [ A] [ B ]
C.肯定错了 D.视规模经济的具体情况而定 6.公共场合某人的吸烟行为会造成 A.生产的外部经济 B.消费的外部经济 C.生产的外部不经济 D.消费的外部不经济 7.某商品的供给曲线的延长线通过原点,则其供给价格点弹性 A.为曲线的斜率 B.恒为 1 C.不可确定 D.随价格的变化而变化 8.由企业购买任何生产要素所发生的成本是 A.显性成本 B.隐性成本 C.变动成本 D.固定成本 9.消费者预算线反映了 A.消费者的收入约束 B.消费者的偏好 C.消费者人数 D.货币的购买力 10.消费者预算线发生平移时,连接消费者各均衡点的曲线被称为 A.需求曲线 B.价格—消费曲线 C.收入—消费曲线 D.恩格尔曲线 11.导致市场失灵的因素是 A.信息不对称 B.公共物品 C.自然垄断 12.垄断会降低经济效率,这是因为 A.当利润最大化时,总收益超过总成本 B.当利润最大化时,价格超过边际成本 C.当利润最大化时,边际收益超过边际成本 D.当利润最大化时,边际成本超过边际收益 13.需求量和价格之所以呈反方向变化,是因为 A.替代效应的作用 B.收入效应的作用 C.上述两种效应同时发生作用 D.以上均不正确 14.如果连续地增加某种生产要素,在总产量达到最大时,边际产量曲线 A.与纵线相交 B.经过原点 C.与平均产量曲线相交 D.与横轴相交 15.在完全竞争市场中,行业的长期供给曲线取决于 A.SAC 曲线最低点的轨迹 B.SMC 曲线最低点的轨迹 C 曲线最低点的轨迹 D.LMC 曲线最低点的轨迹 16.小麦收成下降导致价格上升,准确的说,在这个过程中 A.小麦的供给水平的下降引起需求量下降 B.小麦的供给水平的下降引起需求水平下降 C.小麦供给量的减少引起需求量下降 D.小麦供给量的减少引起需求水平下降 17.当某厂商以最小成本生产出既定产量时,那它 A.总收益为零 B.一定获得最大利润 C.一定未获得最大利润 D.无法确定是否获得最大利润 18.一个消费者想要一单位 X 商品的心情甚于想要一单位 Y 商品,原因是 A.商品 X 有更多的效用 B.商品 X 的价格较低 C.商品 X 紧缺 D.商品 X 是满足精神需要的 19.实施价格歧视的企业在( )的市场索取最高的价格。 A.需求价格弹性最大 B.需求价格弹性最小 C.缺乏需求价格弹性 D.富有需求价格弹性 20.商品 X 和 Y 的价格按相同的比率上升,而收入不变,预算线 A.向左下方平行移动 B.向右上方平行移动 C.不变动 D.不能确定 21.需求曲线斜率为正的充要条件是 A.正常物品 B.替代效应超过收入效应 C.收入效应超过替代效应 D.低档物品且收入效应超过替代效应 22.无差异曲线上任一点上商品 X 和 Y 的边际替代率等于它们的 A.价格之比 B.数量之比 C.边际效用之比 D.边际成本之比 23.垄断竞争区别于寡头垄断在于 A.寡头垄断是不完全竞争 B.垄断竞争企业的需求曲线向下倾斜 C.垄断竞争企业不需要考虑其竞争对手的反应 D.寡头垄断没有竞争 24.完全垄断企业如果处于
微观经济学练习题及答案 (4)
第四篇 市场竞争结构一、判断题(对者打√,错者打×,并说明理由)1. 企业面对的产品市场需求曲线是平均收益曲线( )。
[答] √。
无论完全竞争还是不完全竞争市场,产品市场需求曲线就是平均收益曲线。
因为,AR 为平均收益曲线,P (q )为市场需求曲线。
2. 在完全竞争市场上,企业提高产品价格便能增盈或减亏( )。
[答] ×。
完全竞争市场的价格由市场供求决定,具有完全弹性。
企业是市场价格接受者,如果擅自提价,产销量将降为0,并不能增盈或减亏。
3. 某完全竞争企业的6L =MP ,15K =MP ,3=w ,5=r ,4.0=P ,为实现利润最大,企业将减少L 的投入( )。
[答] ×。
因为根据题中给出的数据知rMP w MP KL < ,L L MP MVP =·w P <。
两个式子中,只要适当提高MP L 和降低MP K ,让两式中的“<”变成“=”,就能实现利润最大化。
所以有三个可行的途径:(1)K 不变,适当减少L 的投入(减少L 的投入使得MP L 增加,同时也降低了MP K ); (2)L 不变,适当增加K 的投入(增加K 能够提高MP L ,同时使得MP K 降低); (3)适当减少L 的投入和适当增加K 的投入。
4. 只要满足MR = MC ,企业必定盈利且最大( )。
[答] ×。
如果满足条件MR = MC ,企业的产销量是最优的——可能盈利最大,也可能亏损最小。
究竟盈利最大还是亏损最小,取决 于的大小关系,或者孰大孰小。
5. 长期均衡时必定短期均衡,但短期均衡时未必长期均衡( )。
[答] √。
长期均衡时,SMC LMC MR ==,也符合短期均衡的条件,但短期均衡时,LMC SMC MR ≠=,不一定符合长期均衡条件。
6. 无论完全竞争还是不完全竞争,企业短期均衡时生产都安排在合理阶段( )。
[答] ×。
微观经济学课后练习题参考答案4
第四章 生产论一、选择题:二、名词解释:1、边际产量:指最后一单位生产要素的投入,所带来的总产量的变化量,简称MP2、平均产量:指平均每单位生产要素投入的产出量,简称AP3、边际报酬递减规律:在技术水平不变的情况下,当把一种可变的生产要素投入到一种或几种不变的生产要素中时,最初这种生产要素的增加会使产量增加,但当它的增加超过一定程度时,增加的产量将要递减。
4、等产量线:表示其它条件不变时,为生产一定的产量所需投入的两种生产要素之间的各种可能组合的轨迹。
5、边际技术替代率:指在产量不变的情况下,当某种生产要素增加一单位时,与另一生产要素所减少的数量的比率。
6、等成本线:指在生产要素价格不变的情况下,生产者花费一定的总成本能购买的两种生产要素最大可能性组合的轨迹。
7、扩展线:指在技术既定和要素价格不变情况下,不同产量水平的最优投入组合点的轨迹。
即不同产量的等产量曲线与等成本线相切的切点联接起来所形成的曲线。
8、规模报酬:规模报酬就是探讨这样一种投入—产出的数量关系,当各种要素同时增加或减少一定比率时,生产规模变动所引起产量的变化情况。
9、规模经济:是指随着生产规模扩大,产品平均成本下降的情况。
三、问答题:1、分析说明生产要素投入的经济区域。
答:生产要素投入的经济区域又称生产要素的合理投入区,指理性的生产者所限定的生产要素投入的数量范围。
具体讲,要分短期和长期两种情况来分析。
(1)如果生产处于短期,并且只有一种生产要素投入数量是可变的,那么该要素的合理投入区处于平均产量最大值点与边际产量等于0的点之间,即L 3<L ﹤L 4 ,在L 3的左边,生产要素投入L 的边际产量超过此时的平均水平,相对于固定投入而言,变动投入数量相对不足,所以理性的生产者不会把投入数量停留在这一范围内。
而在L 4的右边,L 的边际产量为负,很显然,厂商不会把投入增加到这一范围内。
由此可见,如何理性的生产者既不会将生产停留在第Ⅰ阶段,也不会将生产扩张到第Ⅲ阶段,所以,生产只能在第Ⅱ阶段进行。
微观经济学第四章课后练习答案
1、什么是欲望和效用?马斯洛把人的欲望分为哪五个层次?效用和使用价值的关系.答:1)欲望是一种缺乏的感觉与求得满足的愿望。
这也就是说,欲望是不足之感与求足之愿的统一,两者缺一都不能称为欲望。
2)效用是从消费某种物品中所得到的满足程度。
3)马斯洛把人的欲望分为五个层次:第一,基本生理的需要,这是人类最基本的欲望;第二,安全的需要;第三,归属和爱的需要;第四,尊重的需要,这是人更高层次的社会需要;第五,自我实现的需要,这是人最高层次的欲望.2、基数效用论和序数效用论的基本观点是什么?它们各采用何种分析方法?答:1)基数效用论基本观点是:效用是可以用计量并加总求和的,效用的大小是可以用基数(1,2,3…)来表示,正如长度单位可以用米来表示一样。
2)序数效用论是为了弥补基数效用论的缺点而提出来的另一种研究消费者行为的理论。
其基本观点是:效用作为一种心理现象无法计量,也不能加总求和,只能表示出满足程度的高低与顺序,因此,效用只能用序数(第一、第二、第三…)来表示.3)基数效用论采用的是边际效用分析法;序数效用论采用的是无差异曲线分析法.3、什么叫“边际”?总效用和边际效用的关系如何?答:1)边际的含义是增量,指自变量增加1单位所引起的因变量的增加量.2)总效用是指从消费一定量某种物品中所得到的总满足程度;边际效用是指某种物品的消费量每增加1单位所增加的满足程度.消费量变动做引起的效用的变动即位边际效用。
当边际效用为正数时,总效用是增加的;但边际效用为零时,总效用达到最大;当边际效用为负数时,总效用减少。
4、什么是边际效用递减规律?边际效用为什么递减?答:1)随着消费者对某种物品消费量的增加,他从该物品连续增加的消费单位中所得到的边际效用是递减的,这就被称为边际效用递减规律.2)认为边际效用递减规律成立的学派,用两个理由来支持他们的论断。
一是从人的生理和心理的角度来进行解释,认为随着相同消费品的连续增加,从每一单位消费品中所感受到的满足程度和对重复刺激的反应程度是递减的.二是从商品的多用途的角度来进行解释,认为消费者总是将第一单位的消费品用在最重要的用途上,第二单位的消费品用在次重要的用途上,如此等等.这样,消费品的边际效用,就随消费品的用途重要性的递减而递减。
微观经济学 --- 第四章{生产者理论} 参考答案 (上海商学院)
第四章 参考答案一、名词解释1.生产者(producer)是指能够对生产和销售做出统一生产决策,且努力将若干种投入转化为产出的经济单位。
2.生产函数(product function)是指在一定时期内,在技术水平不变的情况下,生产中所运用的各种生产要素的数量和能产生的最大产量之间的关系。
3.生产要素(factors of production)一般是指劳动、土地、资本和企业家才能等。
4.固定比例投入生产函数(fixed-ratio input product function)的形式可以描述为⎪⎭⎫⎝⎛=v K u L Q ,min ,其中Q 为产量,L 、K 分别为劳动和资本的投入量,u 、v 分别为劳动和资本的生产技术系数,表示生产一单位产品所需的劳动和资本投入量。
5.一种可变要素的生产函数:表示在技术水平和其他投入不变的条件下,一种可变生产要素的投入量与其所生产的最大产量之间的关系的函数。
6.短期生产(short-run production)是指生产者来不及调整全部生产要素的数量,至少有一种生产要素的数量是固定不变的时间周期。
7.长期生产(long-run production)是指生产者可以调整全部生产要素的时间周期。
8.柯布----道格拉斯生产函数(Cobb-Douglas product function)的形式可以描述为βαK AL Q =,其中Q 为产量,L 、K 分别为劳动和资本投入量,A 、α和β为参数,α和β分别表示劳动和资本所得在总产量中所占份额,α<0,β<0。
9.总产量(total product)是指与一定的可变要素劳动的投入量相对应的最大产量。
10.平均产量(average product)是总产量与所使用的可变要素劳动的投入之比。
11.边际产量(marginal product)是增加一单位可变要素劳动投入量所增加的产量。
12.边际报酬递减规律(law of diminishing marginal returns)是指在技术水平不变的条件下,连续等量地把一种可变生产要素增加到其他生产要素数量不变的生产过程中,当这种生产要素的投入量小于某一特定值时,增加该要素投入所带来的边际产量是递增的,超过这个特定值时,所带来的边际产量是递减的。
平狄克《微观经济学》课后答案 3-4
CHAPTER 3CONSUMER BEHAVIORChapter 3 builds the foundation to derive the demand curve in Chapter 4. In order to understand demand theory, students must have a firm grasp of indifference curves, the marginal rate of substitution, the budget line, and optimal consumer choice. Utility theory may be discussed independently from consumer choice. Many students find utility functions to be a more abstract concept than preference relationships. However, if you plan to discuss uncertainty in Chapter 5, you will need to cover marginal utility. Even if you cover utility theory only briefly, make sure students are comfortable with the term utility because it appears frequently in Chapter 4.When introducing indifference curves, stress that physical quantities are represented on the two axes. After discussing supply and demand, students may think that price should be on the vertical axis. To develop indifference curves, start with any point in the Cartesian plane and ask for points that are more (and less) preferred. This will divide the plane into four quadrants. Then ask between which points they will be indifferent. Once students grasp the concept of preference points, introduce the notion of a “preference hill.” Using the example of a topographical map or a well-drawn three dimensional figure, point out that a three-dimensional figure is being collapsed into two dimensions.The marginal rate of substitution, MRS , is confusing to students. Some confuse the MRS with the ratio of the two quantities. If this is the case, point out that the slope is equal to the ratio of the rise, ∆Y, and the run, ∆X . This ratio is equal to the ratio of the intercepts of a line just tangent to the indifference curve. As we move along a convex indifference curve, these intercepts and the MRS change. Another problem is the terminology “of X for Y .” This is confusing because we are not substituting “X for Y ,” but Y for one unit of X . Exercise (6) discusses this point, but you may want to offer other exercises to stress it.1. What does transitivity of preferences mean?Transitivity of preferences implies that if someone prefers A to B and prefers B to C , then he orshe prefers A to C .satisfaction. This trading continues until the highest level of satisfaction is achieved.6. Explain why consumers are likely to be worse off when a product that they consume is rationed.If the maximum quantity of a good is fixed by decree and desired quantities are not available forpurchase, then there is no guarantee that the highest level of satisfaction can be achieved. Theconsumer will not be able to give up the consumption of other goods in order to obtain more of therationed good. Only if the amount rationed is greater than the desired level of consumption canthe consumer still maximize satisfaction without constraint. (Note: rationing may imply ahigher level of social welfare because of equity or fairness considerations across consumers.)7. Upon merging with West Germany’s economy, East German consumers indicated a preference for Mercedes-Benz automobiles over Volkswagen automobiles. However, when they converted their savings into deutsche marks, they flocked to Volkswagen dealerships. How can you explain this apparent paradox?Three assumptions are required to address this question: 1) that a Mercedes costs more than aVolkswagen; 2) that the East German consumers’ utility function comprises two goods,automobiles and all other goods evaluated in deutsche marks; and 3) that East Germans haveincomes. Based on these assumptions, we can surmise that while once-East German consumersmay prefer a Mercedes to a Volkswagen, they either cannot afford a Mercedes or they prefer abundle of other goods plus a Volkswagen to a Mercedes alone.8. Describe the equal marginal principle. Explain why this principle may not hold if increasing marginal utility is associated with the consumption of one or both goods.The equal marginal principle states that the ratio of the marginal utility to price must be equalacross all goods to obtain maximum satisfaction. This explanation follows from the same logicexamined in Review Question 5. Utility maximization is achieved when the budget is allocatedso that the marginal utility per dollar of expenditure is the same for each good.If marginal utility is increasing, the consumer maximizes satisfaction by consuming ever largeramounts of the good. Thus, the consumer would spend all income on one good, assuming aconstant price, resulting in a corner solution. With a corner solution, the equal marginalprinciple cannot hold.9. What is the difference between ordinal utility and cardinal utility? Explain why the assumption of cardinal utility is not needed in order to rank consumer choices.Ordinal utility implies an ordering among alternatives without regard for intensity of preference.For example, the consumer’s first choice is preferred to their second choice. Cardinal utilityimplies that the intensity of preferences may be quantified. An ordinal ranking is all that isneeded to rank consumer choices. It is not necessary to know how intensely a consumer prefersbasket A over basket B; it is enough to know that A is preferred to B.10. The price of computers has fallen substantially over the past two decades. Use this drop in price to explain why the Consumer Price Index is likely to substantially understate the cost-of-living index for individuals who use computers intensively.The consumer price index measures the changes in the weighted average of the prices of thebundle of goods purchased by consumers. The weights equal the share of consumer's expenditureson all of the goods in the bundle. A base year is chosen, and the weights for that year are used tocompute the CPI in that and subsequent years. When the price of a good falls substantially then aconsumer will substitute towards that good, altering the share of that consumer's income spent oneach good. By using the base year's weights the CPI does not take into account that large pricechanges alter these expenditure shares, and so gives an inaccurate measure of changes in the costof living.For example, assume Fred spends 10% of his income on computers in 1970, and that Fred'sexpenditure shares in 1970 were used as the weights to calculate Fred's CPI in subsequent years.If Fred's demand for computers was inelastic, then reductions in the price of computers (relativeto other goods) would reduce the share of his income spent on computers. After 1970 a CPI thatused Fred's 1970 expenditure shares as weights would give a 10% weight to the falling price ofcomputers, even though Fred spent less that 10% of his income on computers. So long as theprices of other goods rose, or fell less than 10%, then the CPI gives too little weight to the changesin the prices of other goods, and understates the changes in Fred's cost of living.1. In this chapter, consumer preferences for various commodities did not change during the analysis. Yet in some situations, preferences do change as consumption occurs. Discuss why and how preferences might change over time with consumption of these two commodities:a. cigarettesThe assumption that preferences do not change is a reasonable one if choices are independentacross time. It does not hold, however, when “habit-forming” or addictive behavior is involved, asin the case of cigarettes: the consumption of cigarettes in one period influences their consumptionin the next period.b. dinner for the first time at a restaurant with a special cuisineWhile there may not be anything physically addictive in dining at new and different restaurants, one can become better informed about a particular restaurant. One may enjoy choosing more new and different restaurants, or one may be tired of choosing another new and different place to4.a.c. tothis graphically?, the quantity of butter by B, the Let Bill’s income be represented by Y, the price of butter by PB, and the quantity of margarine by M. Then the general form of the price of margarine by PMbudget constraint is:5.the their a.c. If both Smith and Jones pay the same prices for their refreshments, will their marginal rates ofsubstitution of alcoholic for nonalcoholic drinks be the same or different? Explain.In order to maximize utility, the consumer must consume quantities such that the MRS betweenany two commodities is equal to the ratio of prices. If Smith and Jones are rational consumers,their MRS must be equal because they face the same market prices. But because they havedifferent preferences, they will consume different amounts of the two goods, alcoholic andnonalcoholic. At those different levels, however, their MRS are equal.6. Anne is a frequent flyer whose fares are reduced (through coupon giveaways) by 25 percent after she flies 25,000 miles a year, and then by 50 percent after she flies 50,000 miles. Can you graph the budget line that Anne faces in making her flight plans for the year?In Figure 3.6, we plot miles flown, M , against all other goods, G , in dollars. The budgetconstraint is:Y = P M M + P G G , or.⎪⎪⎭⎫ ⎝⎛-=G M G P P M P Y G The slope of the budget line is -P P M G. In this case, the price of miles flown changes as the number of miles flown changes, so the budget curve is kinked at 25,000 and at 50,000 miles. Suppose P M is $1 per mile for less than or equal to 25,000 miles. Then P M = $0.75 for 25,000 < M ≥ 50,000 and P M = $0.50 for M > 50,000. Also, let P G = $1.00. Then the slope of the budget line from A to B is -1, the slope of the budget line from B to C is -0.75, and the slope of the budget line from B to D is -0.5.8. Suppose that Samantha and Jason both spend $24 per week on video and movie entertainment.U = 12 U = 24Food Clothing Food Clothing 1.0 12.0 1.0 24.01.5 8.02.0 12.02.0 6.03.0 8.012 = 1F + 3C , or ⎪⎪⎭⎝-=34.See Figure 3.10.a.c. What is the utility-maximizing choice of food and clothing? (Hint: Solve the problemgraphically.)The highest level of satisfaction occurs where the budget line is tangent to the highestindifference curve. In Figure 3.10.a this is at the point F = 6 and C = 2. To check this answer,note that it exhausts Jane’s income, 12 = 6P F + 2P C . Also, this bundle yields a satisfaction of 12,as (6)(2) = 12. See Figure 3.10.a.d. What is the marginal rate of substitution of food for clothing when utility is maximized?At the utility-maximizing level of consumption, the slope of the indifference curve is equal to theslope of the budget constraint. Since the MRS is equal to the negative slope of the indifferencecurve, the MRS in this problem is equal to one-third. Thus, Jane would be willing to give upone-third of a unit of clothing for one unit of food.e. Suppose that Jane buys 3 units of food and 3 units of clothing with her $12 budget. Would hermarginal rate of substitution of food for clothing be greater or less than 1/3? Explain.If Jane buys 3 units of food for $1.00 per unit and 3 units of clothing for $3.00 per unit, she wouldspend all her income. However, she would obtain a level of satisfaction of only 9, whichrepresents a sub-optimal choice. At this point, the MRS is greater than one-third, and thus, atthe prices she faces, she would welcome the opportunity to give up clothing to get more food. Sheis willing to trade clothing for food until her MRS is equal to the ratio of prices. See Figure3.10.c.Figure 3.10.c11. The utility that Meredith receives by consuming food F and clothing C is given by u(F,C) = FC. Suppose that Meredith’s income in 1990 is $1,200 and the prices of food and clothing are $1 per unit for each. However, by 1995 the price of food has increased to $2 and the price of clothing to $3. Let 100 represent the cost of living index for 1990. Calculate the ideal and the Laspeyres cost-of-living index for Meredith for 1995. (Hint: Meredith will spend equal amounts on food and clothing with these preferences.)Laspeyres IndexThe Laspeyres index represents how much more Meredith would have to spend in 1995 versus 1990 ifshe consumed the same amounts of food and clothing in 1995 as she did in 1990. That is, the Laspeyresindex for 1995 (L) is given by:L = 100 (Y ')/Ywhere Y’ represents the amount Meredith would spend at 1995 prices consuming the same amount offood and clothing as in 1990: Y ' = P 'F F + P 'C C = 2F + 3C, where F and C represent the amounts of foodand clothing consumed in 1990.We thus need to calculate F and C, which make up the bundle of food and clothing which maximizesMeredith’s utility given 1990 prices and her income in 1990. Use the hint to simplify the problem:Since she spends equal amounts on both goods, P F F = P C C. Or, you can derive this same equationmathematically: With this utility function, MU C = ∆U/∆C = F, and MU F = ∆U/∆F = C. To maximizeutility, Meredith chooses a consumption bundle such that MU F /MU C = P F /P C , which again yields P F F =P C C.From the budget constraint, we also know that:P F F +P C C = YCombining these two equations and substituting the values for the 1990 prices and income yields thesystem of equations:C = F and C + F = 1,200Solving these two equations, we find that:C = 600 and F = 600Therefore, the Laspeyres cost-of-living index is:L = 100(2F + 3C)/Y = 100[(2)(600) + (3)(600)]/1200 = 250Ideal IndexThe ideal index represents how much more Meredith would have to spend in 1995 versus 1990 if sheconsumed amounts of food and clothing in 1995 which would give her the same amount of utility as shehad in 1990. That is, the ideal index for 1995 (I) is given by:I = 100(Y'')/Y, where Y'' = P'F F + P'C C' = 2F' + 3C'where F' and C' are the amount of food and clothing which give Meredith the same utility as she had in1990. F' and C' must also be such that Meredith spends the least amount of money at 1995 prices toattain the 1990 utility level.The bundle (F',C') will be on the same indifference curve as (F,C) and the indifference curve at this point will be tangent to a budget line with slope -(P'F /P'C ), where P'F and P'C are the prices of food and clothing in 1995. Since Meredith spends equal amounts on the two goods, we know that 2F' = 3C'. Since this bundle lies on the same indifference curve as the bundle F = 600, C = 600, we also know that F'C' = (600)(600).Cslope 1P slope F C =-H K slope slope F C =-'H KFigure 3.11Solving for F' yields:F'[(2/3)F'] = 360,000 or F' =[(/),)]32360000 = 734.8From this, we obtain C':C' = (2/3)F' = (2/3)734.8 = 489.9We can now calculate the ideal index: I = 100(2F' + 3C')/Y = 100[2(734.8) + (3)(489.9)]/1200 = 244.9CHAPTER 4INDIVIDUAL AND MARKET DEMANDChapter 4 relies on two important ideas from Chapter 3: the influence of price and income changes on the budget line and optimal consumer choice. The chapter focuses on price changes, individual demand, market demand, demand elasticity, and consumer surplus. These concepts are crucial to understanding the application of demand and supply analysis in Chapter 9 as well as the discussion of market failure in Parts III and IV. Chapter 4 also discusses the derivation of the individual’s demand curve with a discussion of substitution and income effects. The analytical tools students learn in this chapter will be important for the discussion of factor supply and demand in Chapter 14.When discussing the derivation of demand, review how the budget curve pivots around an intercept as price changes and how optimal quantities change as the budget line pivots. Once students understand the effect of price changes on consumer choice, they can grasp the derivation of the price consumption path and the individual demand curve. Remind students that the price a consumer is willing to pay is a measure of the marginal benefit of consuming another unit.When covering the aggregation of individual demands, stress that this is equivalent to the summation of individual demand curves horizontally. Students might think that they can add linear demand functions, e.g., add Q P =-1 plus Q P =-23 to arrive at Q P =-35 or 223Q P =-. Students must be reminded, instead, to write the demand curve in inverse form, with price as a function of quantity, and then add. Thus, we add P = 1 - Q to P = 1 - 2Q to obtain P = 2 - 3Q .Price elasticity of demand and consumer surplus are referred to throughout the text, but the mathematics of price elasticity of demand is difficult for many students. Before discussing the algebra, encourage students to develop an intuitive grasp of elasticity as a measure of the sensitivity of the quantity demanded to changes in price.The easiest algebraic representation of elasticity is %%∆∆QP. As you expand on this expression, make sure thatstudents can distinguish between the slope of a line and an elasticity at each point. One effective teaching method is using a linear demand curve to show that while the slope is constant, the elasticity changes throughout the range of prices. The text relies on this relationship in the discussion of the monopolist’s determination of the profit-maximizing quantity in Chapter 10. The exercises given here are progressive in their difficulty, i.e., the last exercise is much harder than the first. Exercises (1) and (7) assume student understanding of demand elasticity, and a grasp of income elasticity is needed for Exercise (9).Although this chapter introduces consumer surplus, it is not extensively discussed until Chapter 9; producer surplus is covered in Chapter 8. If you postpone the discussion of consumer surplus, do not assign Exercise (4). Once students understand consumer surplus, they will find it to be an extremely useful tool. See Example 4.5.Section 4.2 discusses income and substitution effects. An understanding of these effects is aided by the discussion of normal and inferior goods. This is also a good time to reinforce the concept of relative prices, i.e., a decrease in the price of one good increases the relative price of the other good. Giffen goods, while infrequently encountered, provide a way to discuss the importance of income and substitution effects.Finally, there are other special topics in this chapter and its Appendix. An application of network externalities is given in Example 4.5. The first part of Section 4.6, “Empirical Estimation of Demand,” is straightforward, particularly if you have covered the forecasting section of Chapter 2. However, the l ast part, “The Form of the Demand Relationship,” is difficult for students who do not understand logarithms. The Appendix is intended for students with a background in calculus.1.How is an individual demand curve different from a market demand curve? Which curve is likely to be more price elastic? (Hint: Assume that there are no network externalities.)The market demand curve is the horizontal summation of the individual demand curves. Thegraph of market demand shows the relation between each price and the sum of individualquantities. Because price elasticities of demand may vary by individual, the price elasticity ofdemand is likely to be greater than some individual price elasticities and less than others.2.Is the demand for a particular brand of product, such as Head skis, likely to be more price elastic or price inelastic than the demand for the aggregate of all brands, such as downhill skis? Explain.Individual brands compete with other brands. If the two brands are similar, a small change inthe price of one good will encourage many consumers to switch to the other brand. Becausesubstitutes are readily available, the quantity response to a change in one brand’s price is moreelastic than the quantity response for all brands. Thus, the demand for Head skis is more elasticthan the demand for downhill skis.3.Tickets to a rock concert sell for $10. But at that price, the demand is substantially greater than the available number of tickets. Is the value or marginal benefit of an additional ticket greater than, less than, or equal to $10? How might you determine that value?If, at $10, demand exceeds supply, then consumers are willing to bid up the market price to a levelwhere the quantity demanded is equal to the quantity supplied. Since utility-maximizingconsumers must be willing to pay more than $10, then the marginal increase in satisfaction(value) is greater than $10. One way to determine the value of tickets would be to auction off ablock of tickets. The highest bid would determine the value of the tickets.4.Suppose a person allocates a given budget between two goods, food and clothing. If food is an inferior good, can you tell whether clothing is inferior or normal? Explain.If an individual consumes only food and clothing, then any increase in income must be spent oneither food or clothing (Hint: we assume there are no savings). If food is an inferior good, then,as income increases, consumption falls. With constant prices, the extra income not spent on foodmust be spent on clothing. Therefore, as income increases, more is spent on clothing, i.e. clothingis a normal good.5. Which of the following combinations of goods are complements and which are substitutes? Could they be either in different circumstances? Discuss.a. a mathematics class and an economics classIf the math class and the economics class do not conflict in scheduling, then the classes could beeither complements or substitutes. The math class may illuminate economics, and theeconomics class can motivate mathematics. If the classes conflict, they are substitutes.b. tennis balls and a tennis racketTennis balls and a tennis racket are both needed to play a game of tennis, thus they arecomplements.c. steak and lobsterFoods can both complement and substitute for each other. Steak and lobster can compete, i.e., besubstitutes, when they are listed as separate items on a menu. However, they can also functionas complements because they are often served together.d. a plane trip and a train trip to the same destinationTwo modes of transportation between the same two points are substitutes for one another.e. bacon and eggsBacon and eggs are often eaten together and are, therefore, complementary goods. Byconsidering them in relation to something else, such as pancakes, bacon and eggs can function assubstitutes.6.Which of the following events would cause a movement along the demand curve for U.S.-produced clothing, and which would cause a shift in the demand curve?a. the removal of quotas on the importation of foreign clothesThe removal of quotas will shift the demand curve inward for domestically-produced clothes,because foreign-produced goods are substitutes for domestically-produced goods. Both theequilibrium price and quantity will fall as foreign clothes are traded in a free marketenvironment.b. an increase in the income of U.S. citizensWhen income rises, expenditures on normal goods such as clothing increase, causing the demandcurve to shift out. The equilibrium quantity and price will increase.c. a cut in the industry’s costs of producing domestic clothes that is passed on to the market inthe form of lower clothing pricesA cut in an industry’s costs will shift the supply curve out. The equilibrium price an d quantitywill increase.7. For which of the following goods is a price increase likely to lead to a substantial income (as well as substitution) effect?a. saltSmall income effect, small substitution effect: The amount of income that is spent on salt isrelatively small, but since there are few substitutes for salt, consumers will not readily substituteaway from it. As the price of salt rises, real income will fall only slightly, thus leading to a smalldecline in consumption.b. housingLarge income effect, no substitution effect: The amount of income spent on housing is relativelylarge for most consumers. If the price of housing were to rise, real income would be reducedsubstantially, thereby reducing the consumption of all other goods. However, consumers wouldfind it impossible to substitute for housing, in general.c. theater ticketsSmall income effect, large substitution effect: The amount of income that is spent on theatertickets is relatively small, but consumers can substitute away from the theater tickets by choosingother forms of entertainment (e.g., television and movies). As the price of theater tickets rises,real income will fall only slightly, thus leading to a small decline in consumption.d. foodLarge income effect, no substitution effect: As with housing, the amount of income spent on food isrelatively large for most consumers. Price increases for food will reduce real incomesubstantially, thereby reducing the consumption of all other commodities. Although consumerscan substitute out of particular foods, they cannot substitute out of food in general.8. Suppose that the average household in a state consumes 500 gallons of gasoline per year. A 10-cent gasoline tax is introduced, coupled with a $50 annual tax rebate per household. Will the household be better or worse off after the new program is introduced?If the household does not change its consumption of gasoline, it will be unaffected by thetax-rebate program. It still gets 500 gallons of gasoline. To the extent that the householdreduces its gas consumption through substitution, it must be better off.9. Which of the following three groups is likely to have the most, and which the least, price-elastic demand for membership in the Association of Business Economists?a. studentsThe major difference among the groups is the level of income. We know that if the consumptionof a good constitutes a large percentage of an individual’s income, then the demand for the goodwill be relatively elastic. If we assume that a membership in the Association of BusinessEconomists is likely to be a large expenditure for students, we may conclude that the demand willbe relatively elastic for this group.b. junior executivesThe level of income for junior executives will be larger than that of students, but smaller thanthat of senior executives. Therefore, the demand for a membership for this group will be lesselastic than that of the students but more elastic than that of the senior executives.c. senior executivesThe high earnings among senior executives will result in a relatively inelastic demand formembership.1. The ACME corporation determines that at current prices the demand for its computer chips has a price elasticity of -2 in the short run, while the price elasticity for its disk drives is -1.a. If the corporation decides to raise the price of both products by 10 percent, what will happento its sales? To its sales revenue?We know the formula for the elasticity of demand is:EQP P=%%∆∆.For computer chips, EP= -2, so a 10 percent increase in price will reduce the quantity sold by 20percent. For disk drives, EP= -1, so a 10 percent increase in price will reduce sales by 10 percent.Sales revenue is equal to price times quantity sold. Let TR1 = P1Q1be revenue before the pricechange and TR2 = P2Q2be revenue after the price change.For computer chips:∆TR cc = P2Q2 - P1Q1∆TR cc= (1.1P1 )(0.8Q1 ) - P1Q1 = -0.12P1Q1, or a 12 percent decline.For disk drives:∆TR dd = P2Q2 - P1Q1∆TR dd = (1.1P1 )(0.9Q1 ) - P1Q1 = -0.01P1Q1, or a 1 percent decline.Therefore, sales revenue from computer chips decreases substantially, -12 percent, while the salesrevenue from disk drives is almost unchanged, -1 percent.b. Can you tell from the available information which product will generate the most revenue forthe firm? If yes, why? If not, what additional information would you need?No. Although we know the responsiveness of demand to changes in price, we need to know bothquantities and prices of the products to determine total sales revenue.2. Refer to Example 4.3 on the aggregate demand for wheat. From 1981 to 1990, domestic demand grew in response to growth in U.S. income levels. As a rough approximation, the domestic demand curve in 1990 was QDD= 1200 - 55P. Export demand, however, remained about the same, due to。
微观经济学总复习题及答案
微观经济学总复习题及答案一、选择题1、在得出某种商品的个人需求曲线时,下列因素除哪一种外均保持不变?()A 商品本身的价格;B个人偏好;C 其他商品的价格;D 个人收入2、下列因素中除哪一项外,都会使需求曲线移动?()A 消费者收入变化;B 商品价格变化;C 消费者偏好变化;D 其他相关商品价格变化。
3、商品x和商品y是相互替代的,则x的价格下降将导致()。
A x的需求曲线向右移动;B x 的需求曲线向左移动;C y的需求曲线向右移动;D y 的需求曲线向左移动。
4、某种商品价格下降对其互补品的影响是()。
A 互补品的需求曲线向左移动;B 互补品的需求曲线向右移动;C 互补品的供给趋向向右移动;D 互补品的价格上升。
5、需求的价格弹性是指()。
A 需求函数的斜率;B 收入变化对需求的影响程度;C 消费者对价格变化的反映灵敏程度;D 以上说法都正确。
6、假定某商品的价格从10美元下降到9美元,需求量从70增加到75,则需求为()。
A 缺乏弹性;B 富有弹性;C 单一弹性;D 难以确定。
7、总效用达到最大时()。
A 边际效用为最大;B 边际效用为零;C 边际效用为正;D 边际效用为负。
8、同一条无差异曲线上的不同点表示()。
A 效用水平不同,但所消费的两种商品组合比例相同;B 效用水平相同,但所消费的两种商品组合比例不同;C 效用水平不同,两种商品的组合比例也不相同;D 效用水平相同,两种商品的组合比例也相同。
9、预算线的位置和斜率取决于()。
A 消费者的收入;B商品的价格;C 消费者的收入和商品价格;D消费者的偏好、收入和商品的价格。
10、商品x和y的价格按相同的比例上升,而收入不变,预算线()。
A 向左下方平行移动;B向右上方平行移动;C 向左下方或右上方平行移动D 不变动。
11、如果横轴表示商品x的消费量,纵轴表示商品y的消费量,则预算线绕着它与横轴的交点逆时针转动是因为()。
A 商品x的价格上升;B商品y的价格上升;C 消费者收入下降;D商品x的价格不变,商品y的价格上升。
《微观经济学》(高鸿业第四版)第四章练习题参考答案
第四章1.(1)利用短期生产的总产量(TP)、平均产量(AP)和边际产量(MP)之间的关系,可以完成对该表的填空,其结果如下表:(2)所谓边际报酬递减是指短期生产中一种可变要素的边际产量在达到最高点以后开始逐步下降的这样一种普遍的生产现象。
本题的生产函数表现出边际报酬递减的现象,具体地说,由表可见,当可变要素的投入量由第4单位增加到第5单位时,该要素的边际产量由原来的24下降为12。
2.(1).过TPL曲线任何一点的切线的斜率就是相应的MPL的值。
(2)连接TPL曲线上热和一点和坐标原点的线段的斜率,就是相应的APL的值。
(3)当MPL>APL时,APL曲线是上升的。
当MPL<APL时,APL曲线是下降的。
当MPL=APL时,APL曲线达到极大值。
3.解答:(1)由生产数Q=2KL-0.5L2-0.5K2,且K=10,可得短期生产函数为:Q=20L-0.5L2-0.5*102=20L-0.5L2-50于是,根据总产量、平均产量和边际产量的定义,有以下函数:劳动的总产量函数TP L=20L-0.5L2-50劳动的平均产量函数AP L=20-0.5L-50/L劳动的边际产量函数MP L=20-L(2)关于总产量的最大值:20-L=0解得L=20所以,劳动投入量为20时,总产量达到极大值。
关于平均产量的最大值:-0.5+50L-2=0L=10(负值舍去)所以,劳动投入量为10时,平均产量达到极大值。
关于边际产量的最大值:由劳动的边际产量函数MP L=20-L可知,边际产量曲线是一条斜率为负的直线。
考虑到劳动投入量总是非负的,所以,L=0时,劳动的边际产量达到极大值。
(3)当劳动的平均产量达到最大值时,一定有APL=MPL。
由(2)可知,当劳动为10时,劳动的平均产量APL达最大值,及相应的最大值为:APL的最大值=10MPL=20-10=10很显然APL=MPL=104.解答:(1)生产函数表示该函数是一个固定投入比例的生产函数,所以,厂商进行生产时,Q=2L=3K.相应的有L=18,K=12(2)由Q=2L=3K,且Q=480,可得:L=240,K=160又因为PL=2,PK=5,所以C=2*240+5*160=1280即最小成本。
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第四章 生产论一、选择题:二、名词解释:1、边际产量:指最后一单位生产要素的投入,所带来的总产量的变化量,简称MP2、平均产量:指平均每单位生产要素投入的产出量,简称AP3、边际报酬递减规律:在技术水平不变的情况下,当把一种可变的生产要素投入到一种或几种不变的生产要素中时,最初这种生产要素的增加会使产量增加,但当它的增加超过一定程度时,增加的产量将要递减。
4、等产量线:表示其它条件不变时,为生产一定的产量所需投入的两种生产要素之间的各种可能组合的轨迹。
5、边际技术替代率:指在产量不变的情况下,当某种生产要素增加一单位时,与另一生产要素所减少的数量的比率。
6、等成本线:指在生产要素价格不变的情况下,生产者花费一定的总成本能购买的两种生产要素最大可能性组合的轨迹。
7、扩展线:指在技术既定和要素价格不变情况下,不同产量水平的最优投入组合点的轨迹。
即不同产量的等产量曲线与等成本线相切的切点联接起来所形成的曲线。
8、规模报酬:规模报酬就是探讨这样一种投入—产出的数量关系,当各种要素同时增加或减少一定比率时,生产规模变动所引起产量的变化情况。
9、规模经济:是指随着生产规模扩大,产品平均成本下降的情况。
三、问答题:1、分析说明生产要素投入的经济区域。
答:生产要素投入的经济区域又称生产要素的合理投入区,指理性的生产者所限定的生产要素投入的数量范围。
具体讲,要分短期和长期两种情况来分析。
(1)如果生产处于短期,并且只有一种生产要素投入数量是可变的,那么该要素的合理投入区处于平均产量最大值点与边际产量等于0的点之间,即L 3<L ﹤L 4 ,在L 3的左边,生产要素投入L 的边际产量超过此时的平均水平,相对于固定投入而言,变动投入数量相对不足,所以理性的生产者不会把投入数量停留在这一范围内。
而在L 4的右边,L 的边际产量为负,很显然,厂商不会把投入增加到这一范围内。
由此可见,如何理性的生产者既不会将生产停留在第Ⅰ阶段,也不会将生产扩张到第Ⅲ阶段,所以,生产只能在第Ⅱ阶段进行。
在生产的第Ⅱ阶段,生产者可以得到由于第Ⅰ阶段增加可变要素投入所带来的全部好处,又可以避免将可变要素投入增加到第Ⅲ阶段而带来的不利影响。
因此,第Ⅱ阶段是在生产者进行短期生产的决策区间。
在第Ⅱ阶段的起点处,劳动的平均产量曲线和劳动的边际产量曲线相交,即劳动的平均产量达到最高点。
在第Ⅱ阶段的终点处,劳动的边际产量曲线与水平轴相交,即劳动的边际产量等于零。
至于在生产的第Ⅱ阶段,生产者所应选择的最佳投入数量究竟在哪一点,这一问题还有待于结合成本、收益和利润进行深入的分析。
所以第Ⅱ阶段是厂商短期生产要素投入的经济区域。
如图5所示。
(2)如果生产处于初期,或有两种以上的投入是可变的,那么该两种投入要素的经济区域处于等产量曲线的水平和垂直切点连成的两条曲线之间。
在图6中,横坐标轴表示劳动L的投入量,纵坐标轴表示资本K的投入量。
有一组等产量曲线,这些等产量曲线不仅有斜率为负的部分,也有为正的部分。
当等产量曲线的斜率为负值时,表明两种生产要素可以相互替代,一种生产要素减少,另一种生产要素增加。
图中OE线和OF线之间的区域属于这种情况。
当等产量曲线的斜率为正值时,表明两种生产要素的投入量必须同时增加才能维持总产量不变。
这就是说其中一种生产要素的投入量已达到饱和,在继续使用这种要素时,其边际产量反而为负值,这时不得不靠增加另一种要素的投入量来加以弥补,才能维持总产量不变。
图中OE线和OF线之外的区域属于这种情况。
我们称OE和OF线为脊线。
脊线表明生产要素替代的范围,实际上,合乎理性的厂商不会在脊线以外的区域从事生产,厂商可以在两条脊线之间的区域内从事生产,任意变动其投入要素的组合。
因此这一区域称为生产的经济区域;脊线OE和OF就是生产的经济区域和不经济区域的分界线。
脊线OF上的每一点的要素组合,都表示生产某一既定产量水平所必需使用的最小劳动投入量和可能使用的最大资本投入量;脊线OE上每一点的要素组合,都表示生产某一既定产量水平所必需使用的最小资本投入量和可能使用的最大劳动投入量。
图62、运用边际分析和等产量曲线分析两种方法分析两种生产要素的最优组合。
答:消费者均衡要说明如何使两种物品的组合实现效用最大化。
这里讲的是如何使两种生产要素的组合实现产量最大化。
消费者均衡所用的无差异曲线分析法类似于这里的等产量线分析法。
所不同的是,消费者均衡分析的是消费者的心理感觉,较为抽象,这里分析的产量则具体了。
(1)生产要素最适组合的边际分析生产要素最适组合的原则是:在成本与生产要素价格既定的条件下,应该使所购买的各种生产要素的边际产量与价格的比例相等,即要使每一单位货币无论购买何种生产要素都能得到相等的边际产量。
用公式表示为:PL QL+PKQK=M ①MPL /PL+MPK/PK=MPM②上述①式是限制条件,②式是生产要素最适组合的条件。
(2)生产要素最适组合的等产量线分析①等产量线的含义与特征。
等产量线是表示两种生产要素的不同数量的组合可以带来相等产量的一条曲线,或者说是表示某一固定数量的产品,可以用所需要的两种生产要素的不同数量的组合得出的一条曲线。
等产量线的特征是:第一,等产量线是一条向右下方倾斜的线,其斜率为负值。
这就表明,在生产者的资源与生产要素价格既定的条件下,为达到相同的产量,在增加一种生产要素时,必须减少另一种生产要素。
两种生产要素同时减少,不能保持相等的产量水平。
第二,在同一平面图上,可以有无数条等产量线。
同一条等产量线代表相同的产量,不同的等产量线离原点越远代表产量水平越高,离原点越近代表产量水平越低。
第三,在同一平面图上,任意两条等产量线不能相交。
因为在交点上两条等产量线代表了相同的产量水平,与第二个特征相矛盾。
第四,等产量线是一条凸向原点的线。
这是由边际技术替代率递减所决定的。
②等成本线。
等成本线又称企业预算线。
它是一条表明在生产者的成本与生产要素价格既定的条件下,生产者所能购买的两种生产要素数量的最大组合的线。
等成本线可以写为:C=wL+rK③生产要素的最适组合。
如果把等产量线与等成本线合在一个图上,那么,等成本线必定与无数条等产量线中的一条相切于一点。
在这个切点上,就实现了生产要素最适组合。
如果生产者的货币成本增加,则等成本线向右上方平行移动,不同的等成本线与不同的等产量线相切,形成不同的生产要素组合点,将这些点连接在一起,就得出扩展线。
扩展线的含义是:当生产者沿着这条线扩大生产时,可以始终实现生产要素的最适组合,从而使生产规模沿着最有利的方向扩大。
3、试说明下列说法是否正确:(a)假定生产某产品要使用两种要素,如果这两种要素价格相等,则该生产者最好就是要用同等数量的这两种要素投入。
(b)两种要素A和B的价格如果相等,则产出量一定时,最低成本支出的要素投入组合将决定于等产量曲线斜率为-1之点。
(c)假定生产X产品使用A、B两要素,则A的价格下降必导致B的使用量增加。
(d)在要素A和B的当前使用水平上,A的边际产量是3,B的边际产量是2,每单位要素A的价格是5,B的价格是4,由于B是较便宜的要素,厂商如减少A的使用量而增加B的使用量,就会以更低的成本生产出同样多产量。
解答:(a)不对。
厂商生产一定产量使总成本最小的条件是花费每1元钱购买的两种生产要素所得的边际产量都相等,即MPPA/PA=MPPB/PB,当PA等于PB时,均衡的条件是MPPA=MPPB,而不是A=B。
例如对于生产函数Q=f(K,L)=KL-0.2K2-0.4L2,MPPL=K-0.8L,MPPK=L-0.4K,当PL=PK时,由厂商均衡条件,MPPL=MPPK,即K-0.8L=L-0.4K,可知K=9/7×L,K与L的投入量并不相等。
(b)对。
产出既定时使成本最小的条件可以写成-dB/dA=MPPA/MPPB=PA/PB,如果PA=PB,则-dB/dA=1,即dB/dA=-1,此均衡点即为等产量曲线上斜率为-1的点。
(c)不对。
当A的价格下降时,由于替代效应和产量效应,A的使用量将较前增加,而B的使用量将会减少(参见本章分析说明题第5题图)。
(d)不对。
由于MPPB/MPPA<PB/PA(2/3<4/5)。
这意味着多花1元钱买进B所能增加的产量,小于少花1元钱使用A所减少的产量,也就是说,为了补偿1元钱买进A所损失的产量,所需增加使用的B所费将大于1元钱,因而增加B使用量而同时减少A使用量将可使总成本增加而产量不变。
4、比较规模报酬递减和边际收益递减规律。
答:(1)边际收益递减规律是指在其他要素投入不变的前提下,随着可变要素投入量的增加,在产量达到某点以后,继续增加可变要素的投入会引起该要素的边际报酬递减。
要素包括劳动、资本等。
譬如,在资本等要素数量不变的情况下,劳动增加到某一点之后,劳动的边际产量会递减。
由于每次只涉及一种要素的变化,因此边际收益递减是一个短期概念。
(2)规模报酬递减指在所有要素同时等量变动时,产量的变动幅度小于要素的变动幅度。
比如劳动、资本同时增加一倍,总产量增加小于一倍。
四、计算题:1、已知生产函数为Q=f(K,L)=10KL/(K+L)(a)求出劳动的边际产量及平均产量函数(b)考虑该生产函数的边际技术替代率函数(MRTS)的增减性(c)考虑该生产函数劳动的边际产量函数的增减性解答:(a)劳动的边际产量函数MPPL=dQ/dL=d[10KL/(K+L)]/ dL=[10K(K+L)-10KL]/(K+L)2=10K2/(K+L)2劳动的平均产量函数APPL=Q/L=10KL/(K+L)·1/L=10K/(K+L)(b)生产函数边际技术替代率指产量不变条件下一种生产要素增加的投入量与另一种生产要素相应减少的投入量之比,即-ΔK/ΔL或-dK/dL。
为此,需要从生产函数中先求得K和L之间的关系,然后从这一关系中求得dK/dL。
由生产函数Q=10KL/(K+L)得QK+QL=10KLK(Q-10L)=-QLK=-QL/(Q-10L)则边际技术替代率MRTS=-dK/dL=-d[-QL/(Q-10L)]/ dL=[Q(Q-10L)-QL×(-10)]/(Q-10L)2=Q2/(Q-10L)2要知道边际技术替代率函数的增减性,只要对MRTS求偏导,即MRTS/L=[Q2/(Q-10L)2]/L=Q2·20(Q-10L)/(Q-10L)4=20Q2/(Q-10L)3已知从生产函数中得到K=-QL/(Q-10L)。
可见,此式中分母(Q-10L)<0(因为产量Q,劳动L和资本K都大于零),因此,(Q-10L)3<0,而20Q2>0,因此,MRTS/L=20Q2/(Q-10L)3<0。