平狄克微观经济学课件第14章
平狄克《微观经济学》（第7版）习题详解（第14章-投入要素市场）
平狄克《微观经济学》（第7版）习题详解（第14章-投⼊要素市场）平狄克《微观经济学》（第7版）第14章投⼊要素市场课后复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宝贵的财富，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．为什么当⼚商在产品市场具有垄断势⼒时，它对劳动⼒的需求曲线⽐⼚商是竞争性⽣产时弹性⼩？答：⼚商在产品市场具有垄断势⼒时，它对劳动⼒的需求曲线⽐⼚商是竞争性⽣产时弹性⼩，其原因在于：（1）⼚商对劳动的需求曲线是由劳动的边际收⼊产出L MRP 决定的。
L MRP 指在其他⽣产要素的投⼊量固定不变时追加⼀单位的劳动⼒要素投⼊所带来的收益。
它等于边际物质产品（L MP ）与边际收益（MR ）的乘积，即·L L MRP MP MR =。
（2）在完全竞争市场上，边际收益曲线具有完全弹性并且等于价格P ，故·L L MRP MP P =。
在垄断市场上，边际收益曲线是向下倾斜的，弹性较⼩。
通过边际收⼊产出L MRP 的表达式可以看出，当⼚商在产出品市场具有垄断势⼒时，对劳动的需求曲线⽐⼚商是竞争性⽣产时弹性⼩。
2．为什么劳动供给曲线可能是向后弯曲的？答：劳动供给曲线是⼈们提供的劳动和对劳动所⽀付的报酬之间关系的表现形式。
假设劳动的供给只取决于⼯资，则劳动供给曲线可⽤图14-4表⽰。
此图是向后弯曲的劳动供给曲线。
这是因为，当⼯资较低时，随着⼯资的上升，消费者为较⾼的⼯资所吸引，将减少闲暇，增加劳动供给量。
在这个阶段，劳动供给曲线向右上⽅倾斜。
但是，⼯资上涨对劳动供给的吸引是有限的。
当⼯资涨到⾜够⾼（例如0W ）时，消费者的劳动供给量达到最⼤，此时，如果继续增加⼯资，劳动供给量不会继续增加，反⽽会减少，如当⼯资从0W 提⾼到1W 时，劳动供给则从0L 减少到1L 。
平狄克《微观经济学》(第8版)笔记和课后习题详解复习答案
平狄克《微观经济学》（第8版）笔记和课后习题详解完整版>精研学习䋞>无偿试用20％资料全国547所院校视频及题库全收集考研全套>视频资料>课后答案>往年真题>职称考试第1篇导论：市场和价格第1章绪论1.1复习笔记1.2课后复习题详解1.3课后练习题详解第2章供给和需求的基本原理2.1复习笔记2.2课后复习题详解2.3课后练习题详解第2篇生产者、消费者与竞争性市场第3章消费者行为3.1复习笔记3.2课后复习题详解3.3课后练习题详解第4章个人需求和市场需求4.1复习笔记4.2课后复习题详解4.3课后练习题详解第4章附录需求理论——一种数学的处理方法第5章不确定性与消费者行为5.1复习笔记5.2课后复习题详解5.3课后练习题详解第6章生产6.1复习笔记6.2课后复习题详解6.3课后练习题详解第7章生产成本7.1复习笔记7.2课后复习题详解7.3课后练习题详解第7章附录生产与成本理论——一种数学的处理方法第8章利润最大化与竞争性供给8.1复习笔记8.3课后练习题详解第9章竞争性市场分析9.1复习笔记9.2课后复习题详解9.3课后练习题详解第3篇市场结构与竞争策略第10章市场势力：垄断和买方垄断10.1复习笔记10.2课后复习题详解10.3课后练习题详解第11章有市场势力的定价11.1复习笔记11.2课后复习题详解11.3课后练习题详解第11章附录纵向联合厂商第12章垄断竞争和寡头垄断12.1复习笔记12.2课后复习题详解12.3课后练习题详解第13章博弈论与竞争策略13.1复习笔记13.2课后复习题详解13.3课后练习题详解第14章投入要素市场14.1复习笔记14.2课后复习题详解14.3课后练习题详解第15章投资、时间与资本市场15.1复习笔记15.2课后复习题详解15.3课后练习题详解第4篇信息、市场失灵与政府的角色第16章一般均衡与经济效率16.1复习笔记16.2课后复习题详解16.3课后练习题详解第17章信息不对称的市场17.1复习笔记17.2课后复习题详解17.3课后练习题详解第18章外部性和公共物品18.1复习笔记18.2课后复习题详解附录指定平狄克《微观经济学》教材为考研参考书目的院校列表。
平狄克微观经济学课件
要使市场篮子最大化必须满足两个条件： 1）市场篮子必须位于预算线上；2）商品 组合必须最受消费者的偏好。
.: 消费者行为: 消费者行为
Slide 36
3.3 消费者选择
衣服
40
30
-10C
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Pc = $2 Pf = $1 I = $80
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3.1 消费者偏好
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20 G
10
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.: 消费者行为: 消费者行为
A、B和D三点的商品组合带来的
满足程度是一样的，这些点连结
起来形成无差异曲线U1。而E点要 优于U1曲线上的任一点，而U1曲线 上的任一点都优于H、G点。
E
D U1
食品
30
40
Slide 11
的经济含义。
.: 消费者行为: 消费者行为
Slide 30
3.2 预算约束
收入和价格变化的影响
收入变动 在商品价格不变的前提下，收入增加会导 致预算线平行向右移动。 同样地，在商品价格不变的前提下，收入 减少会导致预算线平行向左移动。
.: 消费者行为: 消费者行为
Slide 31
3.2 预算约束
衣服
80
收入增加导致曲线 向右移动。
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收入减少导致曲线 向左移动。
40
20 L3
(I = L1
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.: 消费者行为: 消费者行为
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160
《微观经济学》平狄克教材
而获得两端收入的可能性小。
Chapter 5
Slide 19
不同概率分布的情形
概率
与工作2相比，工作1的收入 分布较离散，标准差也更大。
0.2
工作2
0.1
工作1
$1000
$1500
Chapter 5
$2000
收入
Slide 20
5.1 风险描述
决策（Decision making）
人们对待风险的态度会影响他们的决策。
Chapter 5
Slide 9
5.1 风险描述
假设Pr1，Pr2…… ，Pr n分别表示每一种可能性
结果的概率，而X1，X2……，X n分别代表每一 种可能性结果的值，那么，期望值的公式为：
E(X) Pr1X1 Pr2 X 2 ... Prn X n
Chapter 5
Slide 10
A
6
0
10
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Chapter 5
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收入
Slide 28
5.2 风险的偏好
风险爱好者
如果消费者在期望收入相同的确定性工作与 不确定性工作中选择了后者，那么，该消费 者就是风险爱好者（risk loving）。
例如：赌博、一些犯罪活动
Chapter 5
Slide 29
5.2 风险的偏好
风险爱好者
2 9,900 2 99.50
Slide 15
5.1 风险描述
计算方差
结果1 结果 2 方差 标准差
工作1 工作2
2,000 1,510
1,000 510
250,000 9,900
500.00 99.50
平狄克《微观经济学》(第7版)习题详解(第14章-投入要素市场)
平狄克《微观经济学》（第7版）第14章 投入要素市场课后复习题详解 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宝贵的财富，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．为什么当厂商在产品市场具有垄断势力时，它对劳动力的需求曲线比厂商是竞争性生产时弹性小？答：厂商在产品市场具有垄断势力时，它对劳动力的需求曲线比厂商是竞争性生产时弹性小，其原因在于：（1）厂商对劳动的需求曲线是由劳动的边际收入产出L MRP 决定的。
L MRP 指在其他生产要素的投入量固定不变时追加一单位的劳动力要素投入所带来的收益。
它等于边际物质产品（L MP ）与边际收益（MR ）的乘积，即·L L MRP MP MR =。
（2）在完全竞争市场上，边际收益曲线具有完全弹性并且等于价格P ，故·L L MRP MP P =。
在垄断市场上，边际收益曲线是向下倾斜的，弹性较小。
通过边际收入产出L MRP 的表达式可以看出，当厂商在产出品市场具有垄断势力时，对劳动的需求曲线比厂商是竞争性生产时弹性小。
2．为什么劳动供给曲线可能是向后弯曲的？答：劳动供给曲线是人们提供的劳动和对劳动所支付的报酬之间关系的表现形式。
假设劳动的供给只取决于工资，则劳动供给曲线可用图14-4表示。
此图是向后弯曲的劳动供给曲线。
这是因为，当工资较低时，随着工资的上升，消费者为较高的工资所吸引，将减少闲暇，增加劳动供给量。
在这个阶段，劳动供给曲线向右上方倾斜。
但是，工资上涨对劳动供给的吸引是有限的。
当工资涨到足够高（例如0W ）时，消费者的劳动供给量达到最大，此时，如果继续增加工资，劳动供给量不会继续增加，反而会减少，如当工资从0W 提高到1W 时，劳动供给则从0L 减少到1L 。
微观经济学第14章课件
都只想搭便车（使用极端正外部性）而不付费。 于是，市场失灵，需要政府干预。
公共物品：非排他非竞争
公共物品的最优数量
由个人需求曲线到市场需求曲线区别：
私人物品是水平（数量Q）相加； 公共物品是垂直（价格P）相加。
（因非排他非竞争）
公共物品与市场失灵
易“免费乘车”致生产不足
即政府可集中计划生产并根据社会福利原则来 分配公共物品。
什么是外部性
外部性及类别
1、外部性（又称外在效应或溢出效应）：没有 在市场交易中反映出来的一个经济主体对其他 经济主体的外在影响。
2、社会成本＝私人成本＋外部成本 3、社会利益＝私人利益＋外部利益 4、负外部性：私人成本＜社会成本 5、正外部性：私人利益＜社会利益
纠正外部影响（纠正市场失灵的办法） ？
故市场机制（谈判交易）不必政府而有效配置资源。
1、若受害者握产权，则从原点开始，有向Qe移动的自然趋势。 2、若排污者握产权，则从Qm开始，……?
成本
或
效益
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外部成本
h
g
a
b
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f
e Qm 经济活 动水平Q
故应“创新”。
科斯定理运用难题：
产权明晰问题； 产权转让问题； 效果实现问题； 分配影响问题。
私人物品。不必政府操心。
2、公共物品：是具有消费的非排他性和非竞争
性，不能依靠市场交易实现有效配置的产品。
非排他非竞争如国防、灯塔、无线电视、环保等。 公共物品因其非排他性──或在技术上不能排他、
或排他成本很高而不可实施， 导致“搭便车”或称“免费搭车”。
如流域范围无法用市场机制自发修水坝。 又如1970年美通用汽车向市场推出汽车污染物排放
平狄克微观经济学课件 (11)
5 of 32
FIGURE 14.3
A SHIFT IN THE SUPPLY OF LABOR
When the supply of labor facing the firms is S1, the firm hires L1 units of labor at wage w1.
But when the market wage rate decreases and the supply of labor shifts to S2, the firm maximizes its profit by moving along the demand for labor curve until the new wage rate w2 is equal to the marginal revenue product of labor. As a result, L2 units of labor are hired.
(14.4)
Equation (14.4) shows that both the hiring and output choices of the firm follow the same rule: Inputs or outputs are chosen so that marginal revenue (from the sale of output) is equal to marginal cost (from the purchase of inputs). This principle holds in both competitive and noncompetitive markets.
•
(14.3)
4 of 32
FIGURE 14.2
平狄克《微观经济学》(第8版)配套题库(下册)-章节题库-投入要素市场【圣才出品】
第14章投入要素市场一、单项选择题1．完全竞争条件下，厂商使用要素的边际收益是指（）。
A ．边际产品价值B ．边际产品C ．产品价格D ．边际产品与要素价格之积【答案】A【解析】边际产品价值（VMP ）是指在完全竞争条件下，厂商增加一单位要素投入所增加的产量的销售值，是一种特殊的边际收益产品。
2．在产品市场与要素市场均为完全竞争的企业内，工人工资率为10，边际产量为5，则产品价格为（）。
A ．2.0B ．0.5C ．1.0D ．5.0【答案】A【解析】完全竞争厂商的利润最大化条件为MP P W ⨯=，即有510P ⨯=，可得产品价格为2。
3．完全竞争厂商对要素的需求曲线可以用（）表示。
A．VMP曲线B．MPP曲线C．MFC曲线D．以上都不是【答案】A【解析】完全竞争厂商对要素的需求曲线可以用W VMP MP P==⨯表示，由利润最大化条件可知，在VMP曲线上，工资W和价格P存在一一对应关系，因而可以用来表示要素需求曲线。
4．在不完全竞争的产品市场和完全竞争的要素市场中，若一种要素可变，则该厂商对要素的需求曲线由（）给出。
A．VMP曲线B．MPP曲线C．MFC曲线D．MRP曲线【答案】D【解析】在不完全竞争的产品市场和完全竞争的要素市场中，该厂商对要素的需求曲线就是边际收益产品曲线。
5．完全竞争产品市场的生产要素需求曲线与不完全竞争产品市场的生产要素需求曲线相比（）。
A．两者重合B．更加陡峭C．更加平坦D．无法确定【答案】C【解析】完全竞争市场的生产要素需求曲线为W VMP MP P==⨯，垄断市场的生产要素需求曲线为W MRP MR MP==⨯，由于边际收益小于市场价格且向右下方倾斜，因此完全竞争市场的生产要素需求曲线比垄断市场更为平坦。
6．表示要素边际生产力的边际收益产品等于（）。
A．边际产品与产品价格之积B．边际产品与边际收益之积C．边际收益与产品价格之积D．边际产品价值【答案】B【解析】边际收益产品是指在其他生产要素的投入量固定不变时追加一单位的某种生产要素投入所带来的收益。
平狄克 微观经济学 第七版 ppt课件
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第二章 消费者行为理论
任何经济体制实际上都是人的集合，因此， 经济学很自然地从个人行为开始进行分析：
4、需求的变动不存在时滞。
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需求的价格弹性与销售收入
价格弹性大的物品，降价可以提高销售 收入；价格弹性小的物品，提价可以提 高销售收入。
马歇尔于1890年发表的 《经济学原理》，被看作是
与斯密《国富论》、李嘉图
《赋税原理》齐名的划时代
著作，成为当时最有影响的
完整版微观经济学(平狄克)图像.pptx
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• 收入变化
当收入—需求曲线的 斜率为负数时:
需求量随收入的 增加而减少。需求的 收入弹性为负值.
若价格相对比率保持不变
如果两种商品价格均上升， 但价格相对比率保持不变， 则预算线的斜率不变。但 预算线将与原来的预算线 平行并向内移动。
如果两种商品价格均下降， 但价格相对比率保持不变， 则预算线的斜率不变。但 预算线将与原来的预算线 平行并向外移 Solutions
K = C/r - (w/r)L
• 成本最小化的资本与劳动组合可写成：
– 在给定产出水平下，成本最小满足的条
件是：每1美元的投入增加到生产过程中
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去会有与之等值的产出增加。
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– 长期边际成本变化导致长期平均成本的变 化:
• 如果长期边际成本小于长期平均成本 （ LMC < LAC）, 长期平均成本（LAC） 将 下降；
Q = 8 - 2P
Ep = -1 2
线性需求曲线
Q = a - bP
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汽油的情况
耐用消费品如汽车
初级铜的情况
再生铜的情况
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短期弹性 和
长期弹性
价格控制的效应 价格
P0
Pmax
Q0
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S
如果被设定为不超过 Pmax, 产品供给下降到Q1， q需求数 量增加到Q2. 供给和需求之间
平狄克《微观经济学》(第7版)【教材精讲+考研真题解析】讲义与视频课程【32小时高清视频】
平狄克《微观经济学》（第7版）【教材精讲＋考研真题解析】讲义与视频课程【32小时高清视频】目录第一部分开篇导读[0.5小时高清视频讲解]第二部分辅导讲义[27小时高清视频讲解]第1章绪论第2章供给和需求的基本原理2.1 本章框架结构图2.2 重难点解读第3章消费者行为3.1 本章框架结构图3.2 重难点解读第4章个人需求和社会需求4.1 本章框架结构图4.2 重难点解读第5章不确定性与消费者行为5.1 本章框架结构图5.2 重难点解读第6章生产6.1 本章框架结构图6.2 重难点解读第7章成产成本7.1 本章框架结构图7.2 重难点解读第8章利润最大化和竞争性供给8.1 本章框架结构图8.2 重难点解读第9章竞争性市场分析9.1 本章框架结构图9.2 重难点解读第10章市场势力：垄断与买方垄断10.1 本章框架结构图10.2 重难点解读第11章有市场势力的定价11.1 本章框架结构图11.2 重难点解读第12章垄断竞争和寡头竞争12.1 本章框架结构图12.2 重难点解读第13章博弈论和竞争策略13.1 本章框架结构图13.2 重难点解读第14章投入要素市场14.1 本章框架结构图14.2 重难点解读第15章投资、时间及资本市场15.1 本章框架结构图15.2 重难点解读第16章一般均衡与经济效率16.1 本章框架结构图16.2 重难点解读第17章信息不对称市场17.1 本章框架结构图17.2 重难点解读第18章外部性和公共品18.1 本章框架结构图18.2 重难点解读第三部分名校考研真题名师精讲及点评[4.5小时高清视频讲解]一、名词解释二、简答题三、计算题四、论述题内容简介本书特别适用于参加研究生入学考试指定考研参考书目为平狄克《微观经济学》的考生，也可供各大院校学习平狄克《微观经济学》的师生参考。
平狄克所著的《微观经济学》（中国人民大学出版社）被列为“十一五”国家重点图书出版规划项目，是我国众多高校采用的经济学优秀教材，也被众多高校（包括科研机构）指定为“经济类”专业考研参考书目。
微观经济学课件平狄克版课件
Chapter 1
13
经济制度
■ 计划经济制度：政府公共部门决策 ■ 市场经济制度：私人部门决策 ■ 混合经济
Chapter 1
14
制度与激励
■ 不同的制度产生不同的激励，进而决定人的选 择行为，最终对经济效率产生重大影响 ■ 例子：大学寝室分面条的故事
Chapter 1
15
1.1.2 价格和市场
■ 经济个体所有的选择都是在他们面临的 价格基础上作出的。 ■ 价格是由买者和买者在市场中相互作用 决定的。 ■ 市场是通过相互作用决定一种或一系列 商品价格的买卖双方的集合。
Chapter 1
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1.2 经济学的研究方法
■ 理论和模型 ■ 均衡分析和边际分析 ■ 静态、比较静态和动态分析 ■ 实证分析和规范分析
■ 为谁生产：生产出来的巧克力或汽车是分给你 多些还是分给我多些？
Chapter 1
12
资源利用的基本问题
■ 为什么资源得不到充分利用？（充分就业）
■ 对给定的资源，为什么产量时高时低？（经济 波动）
■ 货币购买力的变动对汽车和巧克力的生产有什 么影响？（通货膨胀）
■ 在给定的资源条件下，如何使社会总产出越来 越多？（经济增长、技术进步、资本积累、制度 ）
第1章 绪论
Chapter 1
1
本章要点
■ 微观经济学的研究主题 ■ 经济学的研究方法 ■ 市场与市场价格 ■ 名义价格与实际价格 ■ 为什么要学习微观经济学
Chapter 1
2
经济学的主题
■ 经济学？经济学的两个主要分支：微观经济学 和宏观经济学。
■ 微观经济学研究单个经济个体(消费者、劳动 者、资金所有者、土地所有者、企业)的行为及 其相互作用(形成市场)。
平狄克《微观经济学》(第7版)笔记(第14章 投入要素市场)
平狄克《微观经济学》（第7版）第14章 投入要素市场复习笔记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宝贵的财富，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．竞争性要素市场生产要素指厂商为从事产品生产和提供劳务而投入的各种经济资源，通常也被称为生产资源。
生产要素通常被分为四种，即劳动、土地、资本和企业家才能。
一个竞争性要素市场是有大量生产要素出售者和购买者的市场。
由于没有任何单个出售者或购买者能够影响要素的价格，每个人都是价格接受者。
（1）引致需求产品市场上的需求和生产要素市场的需求具有不同的性质。
在产品市场上，需求来自消费者，消费者为了直接满足自己的需要而产生对商品的需求。
而厂商购买生产要素并不是为了满足自身的需求，而是为了生产和出售这些商品以获得收益。
因而引致需求指消费者对商品的需求间接地引致厂商对生产要素的需求。
消费者对商品的需求为直接需求。
（2）只有一种要素是可变要素时对投入要素的需求：厂商雇佣和产出遵循的原则 厂商为了使利润最大化，在使用生产要素时遵循边际成本等于边际收益的原则，亦即边际收益产品等于边际要素成本的原则。
要素的“边际收益”即增加一单位要素所增加的收益，它用要素的边际收益产品MRP 来表示。
因为对竞争性厂商来说，MR P =，得到MRP MP P =⨯。
只有一种要素是可变要素，例如资本不变而只有劳动力可变时，竞争性厂商使用要素的原则为：MRP w =，即L MR w MP =／。
由于L MP 衡量每单位投入的额外产出，因此等式的右面衡量一单位额外产出的成本（工资率乘以生产一单位产出所需要的劳动），即生产的边际成本。
平狄克微观经济学第六版第十四章课后答案解析
CHAPTER 14MARKETS FOR FACTOR INPUTSThe following two chapters examine the markets for labor and capital. Although the discussion in this chapter is general, most of the examples refer to labor as the only variable input to production, with the exception of Example 14.1, which discusses “The Demand for Jet Fuel”by airlines. Labor demand and supply are discussed in the first section, and the competitive factor market equilibrium and economic rent are discussed in the second section. Section 14.3 explores the factor market structure for the case where the buyer has monopsony power, and section 14.4 explores the case of monopoly power on the part of the seller of the factor.An understanding of this chapter relies on concepts from Chapters 4 through 8 and 10. If you have just covered Chapters 11-13, you might begin by reviewing marginal product, marginal revenue, and cost minimization. You should then discuss marginal revenue product and the profit-maximizing condition MRP L = w. Explain why we are only interested in the portion of the MP curve below the average product curve (the downward-sloping portion). The derivation of the firm’s demand curve for labor is straightforward when labor is the only factor, but becomes more complicated when there are several variable inputs. In particular, you might explain why the MRP L curve shifts as the firm substitutes one input for another in production in response to a price change by noting that the MRP L curve is drawn for a fixed level of the other variable input.When presenting the market labor demand curve, explain that since the input prices change as more inputs are demanded, the market demand curve is not simply the summation of individual demand curves. You can extend the presentation of price elasticity of input demand (see Example 14.1) by discussing the conditions leading to price sensitivity. Elasticity is greater (1) when the elasticity of demand for the product is higher, (2) when it is easy to substitute one input for another, and (3) when the elasticity of supply is higher for other inputs. Elasticity of supply, which was discussed in Chapter 2, is reintroduced in Example 14.2. You should also distinguish between short-run and long-run elasticity (see Figure 14.6).If you have already covered substitution and income effects, the students will be ready for the derivation of the backward-bending supply curve for labor. Although Figure 14.9 is a straightforward application of these tools, students are often confused by the plotting of income against leisure. Point out that this is just another type of utility maximization problem where the two goods are leisure and income. Income can be thought of as the consumption of goods other than leisure, in that more income buys more goods. You can also implicitly assume that the price of other goods is $1 and the price of leisure is the wage. The supply of labor curve is derived by changing the wage and finding the new level of hours worked. An individual’s supply curve of labor is backward bending only when the income effect dominates the substitution effect and leisure is a normal good. Show typical supply curves for each group in Table 14.2. For anexperimental study of the labor-leisure trade-off see Battalio, Green, and Kagel, “Income-Leisure Tradeoff of Animal Workers,”American Economic Review (September 1981).Section 14.2 brings together labor demand and supply for both competitive and monopolistic product markets. Although economic rent was presented in Chapter 8, it is reintroduced with more detail here. In Section 14.3, carefully explain why the marginal expenditure curve is above the average expenditure curve for a monopsonist (see Figure 14.14). You can discuss how a monopsonist would price discriminate, e.g., pay a different wage rate to each employee. With perfect price discrimination, the marginal revenue expenditure curve would coincide with the average expenditure curve. Although monopsony exists in some markets, the exercise of monopsony power is rare because of factor mobility. However, the employment of athletes by the owners of professional teams provides a good example (see Example 14.4 “Monopsony Power in the Market for Baseball Players”). On this same topic, see Sommers and Quinton, “Pay and Performance in Major League Baseball: The Case of the First Family of Free Agents,”Journal of Human Resources (Summer 1982). Section 14.4 discusses the case of unions to explore monopoly power on the part of the seller of the input.* *1. Why is a firm’s demand for labor curve more inelastic when the firm has monopoly power in the output market than when the firm is producing competitively?The firm’s demand curve for labor is determined by the incremental revenue fromhiring an additional unit of labor known as the marginal revenue product of labor:MRP L= (MP L)(MR), the additional output (“product”) that the last workerproduced, times the additional revenue earned by selling that output. In acompetitive industry, the marginal revenue curve is perfectly elastic and equal toprice. For a monopolist, marginal revenue is downward sloping. As more labor ishired and more output is produced, the monopolist will charge a lower price andmarginal revenue will diminish. All else the same, marginal revenue product will besmaller for the monopolist. This implies that the marginal revenue product for themonopolist is more inelastic than for the competitive firm.2. Why might a labor supply curve be backward bending?A backward-bending supply curve for labor may occur when the income effect of anincrease in the wage rate dominates the substitution effect. Labor supply decisionsare made by individuals choosing the most satisfying combination of work and other(leisure) activities. With a larger income, the individual can afford to work fewerhours: the income effect. As the wage rate increases, the value of leisure time (theopportunity cost of leisure) increases, thus inducing the individual to work longerhours: the substitution effect. Because the two effects work in opposite directions,the shape of an individual’s labor supply curve depends on the individual’spreferences for income, consumption, and leisure.3. How is a computer company’s demand for computer programmers a derived demand?A computer company’s demand for inputs, including programmers, depends onhow many computers it sells. The firm’s demand for programming labor dependson (is derived from) the demand it faces in its market for computers. As demandfor computers shifts, the demand for programmers shifts.4. Compare the hiring choices of a monopsonistic and a competitive employer of workers. Which will hire more workers, and which will pay the higher wages? Explain.Since the decision to hire another worker means the monopsonist must pay a higherwage for all workers, and not just the last worker hired, its marginal expenditurecurve lies above the input supply curve (the average expenditure curve). Themonopsonist’s profit-maximizing input demand, where the marginal expenditurecurve intersects the marginal revenue product curve, will be less than thecompetitor’s profit-maximizing input choice, where the average expenditure curveintersects the demand curve. The monopsonist hires less labor, and the wage paidwill be less than in a competitive market.5. Rock musicians sometimes earn over $1 million per year. Can you explain such large incomes in terms of economic rent?Economic rent is the difference between the actual payment to the factor ofproduction and the minimum amount that the factor is willing to accept. In thiscase, you might assume that there are a limited number of top-quality rockmusicians who will continue to play rock music no matter what they are paid. Thisresults in a perfectly inelastic supply curve, or something close to it. Given the highdemand for rock music, the wage will be very high and there will be a lot ofeconomic rent. If there was a larger supply of top-quality rock musicians, or a moreelastic supply, then the economic rent would be smaller.6. What happens to the demand for one input when the use of a complementary input increases?If the demand for the complementary input increases, the demand for the giveninput will increase as well. When demand for the complementary input increases,there is an increase in the quantity hired and possibly the price paid. Both of thesechanges will increase the MRP of the given input, and hence will increase thequantity hired and possibly the price paid. Whether the prices of the inputsincreases depends on the degree of monopsony power on the part of the firm.7. For a monopsonist, what is the relationship between the supply of an input and the marginal expenditure on it?The decision to increase employment means the monopsonist must pay all units thehigher price, and not just the last unit hired. Therefore, its marginal expenditurecurve lies above the input supply curve (the average expenditure curve). Hiringmore labor will increase the marginal expenditure, which will increase the averageexpenditure. If the average expenditure is increasing, then the marginalexpenditure must be greater than the average expenditure.8. Currently the National Football League has a system for drafting college players by which each player is picked by only one team. The player must sign with that team or not play in the league. What would happen to the wages of newly drafted and more experienced football players if the draft system were repealed, and all teams could compete for college players?The National Football League draft and reserve clause (a primary issue in the 1987-1988 season’s strike) creates a monopsonist cartel among the owners of NFL teams.If the draft system were repealed, competition among teams would increase wagesof football players to the point where the marginal revenue product of each playerwould be equal to the player’s wage.9. The government wants to encourage individuals on welfare to become employed. It is considering two possible incentive programs for firms.A. Give the firm $2 per hour for every individual on welfare who is hired.B. Give each firm that hires one or more welfare workers a payment of $1000 peryear, irrespective of the number of hires.To what extent is each of these programs likely to be effective at increasing the employment opportunities for welfare workers?Firms will hire additional labor as long as the extra benefit is greater than the extracost of hiring the worker, or until MRP L = w. Option A would be effective becauseif the firm receives $2 per hour for every welfare worker hired then the effectivewage paid, w, will fall and the firm will find it optimal to hire more labor until thebenefits (MRP L) again equal the costs (w) at the margin. Option B would beeffective at increasing employment opportunities also in that if the firm hires anindividual who has been on welfare they will then receive $1000. However, plan Bis not necessarily as effective as plan A given the firm only receives one lump sumpayment regardless of the number of welfare workers hired. In this case the firmonly has an incentive to hire the one welfare worker, though they may of coursechoose to hire more than one welfare worker.10. A small specialty cookie company, whose only variable input is labor, finds that the average worker can produce 50 cookies per day, the cost of the average worker is $64 per day, and the price of a cookie is $1. Is the cookie company maximizing its profit? Explain.The marginal product of labor is 50 (cookies per day) and the price per cookie is 1($ per cookie) so the marginal revenue product is $50/day. Since this is less thanthe wage of $64 per day the cookie company is not maximizing profit. They areemploying too much labor since the cost of labor is greater than the benefit oflabor at the margin, and are therefore producing too many cookies.11. A firm uses both labor and machines in production. Explain why an increase in the average wage rate causes both a movement along the labor demand curve and a shift of the curve.An increase in the wage rate causes an upward movement along the labordemand curve. For any given marginal revenue product curve, the firm will findthat they want to hire fewer workers when the wage increases (an upwardmovement). However, when the wage increases the marginal cost will increasewhich will reduce desired output. When output falls, the firm will not need asmany machines and the marginal product of labor curve will shift to the left,assuming machines and labor are complementary. This will also reduce thedemand for labor.1. Suppose that the wage rate is $16 per hour, and the price of the product is $2. Values for output and labor are in units per hour.q L0 020 135 247 357 465 570 6a.Find the profit-maximizing quantity of labor.From the information given above, calculate the marginal product of labor, theextra output produced by hiring one more unit of labor, and then multiply by priceto get the marginal revenue product of labor. To find the profit-maximizingquantity of labor, use the rule that the firm wants to hire labor only as long as themarginal revenue product of labor is greater than the nominal wage, or up to thepoint where the marginal revenue product of labor is equal to the nominal wage.From the table below, the firm will hire 5 units of labor.b.Suppose that the price of the product remains at $2 but that the wage rate increasesto $21. Find the new profit-maximizing quantity of labor.The above table does not change for this part of the problem. However, the firmno longer wants to hire 5 units of labor because the benefit of the 5th unit ($16 perhour) is less than the cost of the 5th unit ($21 per hour). The firm would only hire3 units of labor per hour since in this case the benefit still exceeds the cost at themargin. The firm would stick with 3 units instead of 4 unless fractional units arepossible. At L=4 the cost is greater than the benefit so you lose profit by hiringthe 4th unit of labor.c.Suppose the price of the product increases to $3 and the wage remains at $16 perhour. Find the new profit-maximizing quantity of labor.A change in the price of the product will not change the marginal product of labor,but it will change the marginal revenue product of labor. The new marginalrevenue product of labor is given in the table below. The firm will still want tohire 5 units of labor, as in part a above. It will not hire the 6th unit because theextra benefit is less than the extra cost. Profit will be greater than in part a.d.Suppose that the price of the product remains at $2 and the wage remains at $16, butthere is a technological breakthrough that increases output by 25% for any given level of labor. Find the new profit-maximizing quantity of labor.The technological breakthrough changes the number of units of output producedby a given number of units of labor, and hence changes the marginal product andthe marginal revenue product of labor. The new output values are found bymultiplying the old values by 1.25. This new information is given in the tablebelow. The firm will still choose to hire 5 units of labor. Profit will be greaterthan in part a.2. Assume that workers whose incomes are less than $10,000 currently pay no federal income taxes. Suppose a new government program guarantees each worker $5,000, whether or not he or she earns any income. For all earned income up to $10,000, the worker must pay a 50-percent tax. Draw the budget line facing the workers under this new program. How is the program likely to affect the labor supply curve of workers?The budget line for workers under this program is a straight line at $5,000. This lineis shown in the figure and table below. Workers earn $5,000 whether they work ornot. If workers work only to earn income, i.e., there are no other benefits such as“getting out of the house”or “gaining experience,”there is no incentive towork under the new program. Only wages yielding incomes greater than $10,000will result in a positive labor supply.Figure 14.2Income After TaxIncome GovernmentSubsidyTotalIncome0 0 5,000 $5,000$1,000 500 4,500 5,0002,000 1,000 4,000 5,0003,000 1,500 3,500 5,0004,000 2,000 3,000 5,0005,000 2,500 2,500 5,0006,000 3,000 2,000 5,0007,000 3,500 1,500 5,0008,000 4,000 1,000 5,0009,000 4,500 500 5,00010,000 5,000 0 5,0003. Using your knowledge of marginal revenue product, explain the following:a. A famous tennis star is paid $100,000 for appearing in a 30-second televisioncommercial. The actor who plays his doubles partner is paid $500.Marginal revenue product of labor, MRP L, is equal to marginal revenue from anincremental unit of output multiplied by the marginal product from an incrementalunit of labor, or in other words, the extra revenue generated by having the tennisstar appear in the ad. The famous tennis star is able to help increase revenues farmore than the actor, so he is paid much more than the actor. The wage of theactor is determined by the supply and demand of actors willing to play tennis withtennis stars.b. The president of an ailing savings and loan is paid not to stay in his job for the last twoyears of his contract.The marginal revenue product of the president of the ailing savings and loan is likelyto be negative and therefore, the savings and loan is better off by paying thepresident not to show up. They have calculated that they will lose less (or gainmore) by paying the president off and hiring someone else.c. A jumbo jet carrying 400 passengers is priced higher than a 250-passenger model eventhough both aircraft cost the same to manufacture.The ability of the larger jet to generate more revenue increases its value to theairline, and therefore the airline is willing to pay more for it.4. The demands for the factors of production listed below have increased. What can you conclude about changes in the demand for the related consumer goods? If demands for the consumer goods remain unchanged, what other explanation is there for an increase in derived demands for these items?a. Computer memory chipsIn general, an increase in the demand for a good increases the demand for its factorinputs. The converse is not necessarily true; i.e., an increase in the demand forfactor inputs does not necessarily imply an increase in the demand for the finalproduct. The demand for an input may increase due to a change in the use ofother inputs in the production process. As the price of another input increases, itsdemand falls and the demand of substitutable inputs rises. In this case, the increasein the demand for computer memory chips must have been caused by an increase inthe demand for personal computers given that computer memory chips are usedonly in computers, and there are no substitutes for computer memory chips.b. Jet fuel for passenger planesWith an increase in the demand for jet travel, the demand for jet fuel will increase.There are no substitutes for jet fuel.c. Paper used for newsprintGiven the paper is being used to print newspapers then there must have been anincrease in the circulation of newspapers.d. Aluminum used for beverage cansWith an increase in demand for cold drinks in the summer, the seasonal demand foraluminum increases, so this is one possible explanation. Alternatively, if glass orplastic have become more expensive then this may affect the demand for aluminum.Finally, changes in the market for recycled aluminum may affect the demand fornew aluminum.5. Suppose there are two groups of workers, unionized and nonunionized. Congress passesa law that requires all workers to join the union. What do you expect to happen to the wage rates of formerly nonunionized workers? of those workers who were originally unionized? What have you assumed about the union’s behavior?In general, we expect that nonunionized workers are earning lower wages thanunionized workers. If all workers are forced to join the union, it would bereasonable to expect that the nonunionized workers will now receive higher wagesand the unionized workers will receive a wage that could go either way. There are acouple of items to consider. First, the union now has more monopoly power in thatthere are no nonunion workers to act as substitutes for union workers. This givesmore power to the union, which means higher wages can in general be negotiated.However, the union now has more members to satisfy. If wages are kept at a highlevel, there will be fewer jobs, and hence some previously nonunionized workersmay end up with no job. The union may wish to trade off some of the wage for aguarantee of more jobs. The average income of all workers will rise if labor demandis inelastic and will fall if labor demand is elastic.6. Suppose a firm’s production function is given by Q = 12L - L2, for L = 0 to 6, where L is labor input per day and Q is output per day. Derive and draw the firm’s demand for labor curve if the firm’s output sells for $10 in a competitive market. How many workers will the firm hire when the wage rate is $30 per day? $60 per day? (Hint: The marginal product of labor is 12 - 2L.)The demand for labor is given by the marginal revenue product of labor. This isequal to the product of marginal revenue and the marginal product of labor: MRP L =(MR)(MP L). In a competitive market, price is equal to marginal revenue, so MR = 10.We are given MP L = 12 - 2L (the slope of the production function).Figure 14.6Therefore, the MRP L = (10)(12 - 2L). The firm’s profit-maximizing quantity of laboroccurs where MRP L = w. If w = 30, then 30 = 120 - 20L at the optimum. Solving forL yields 4.5 hours per day. Similarly, if w = 60, solving for L yields 3 hours per day.7. The only legal employer of military soldiers in the United States is the federal government. If the government uses its monopsonistic position, what criteria will it employ when figuring how many soldiers to recruit? What happens if a mandatory draft is implemented?Acting as a monopsonist in hiring soldiers, the federal government would hiresoldiers until the marginal value of the last soldier is equal to his or her pay. Thereare two implications of the government’s monopsony power: fewer soldiers arehired, and they are paid less than their marginal product. When a mandatory draftis implemented, even fewer professional soldiers are hired. Wages for volunteersoldiers fall, pushed down by the fact that wages of the draftees can be very low.8. The demand for labor by an industry is given by the curve L = 1200 - 10w, where L is the labor demanded per day and w is the wage rate. The supply curve is given by L = 20w. Whatis the equilibrium wage rate and quantity of labor hired? What is the economic rent earned by workers?The equilibrium wage rate is determined where quantity of labor supplied is equal tothe quantity of labor demanded:20w = 1,200 - 10w, or w = $40.Substituting into either the labor supply or labor demand equations, we find theequilibrium quantity of labor is 800:L= (20)(40) = 800,SandL D = 1,200 - (10)(40) = 800.Economic rent is the summation of the difference between the equilibrium wage andthe wage given by the labor supply curve. Here, it is the area above the laborsupply curve up to L = 800 and below the equilibrium wage. This triangle’s area is(0.5)(800)($40) = $16,000.9. This exercise is a continuation of Exercise 8. Suppose now that the only labor available is controlled by a monopolistic labor union that wishes to maximize the rent earned by union members. What will be the quantity of labor employed and the wage rate? How does your answer compare with your answer to Exercise 8? Discuss. (Hint: The union’s marginal revenue curve is given by L = 1200 - 20w.)Recall that the monopolist chooses output by setting marginal revenue equal to themarginal cost of supplying one more unit of output, as opposed to the competitivefirm which chooses output by setting price equal to marginal cost, or in other wordsproducing where supply intersects demand. The monopolistic labor union acts inthe same way. To maximize rent in this case, the union will choose the number ofworkers hired so that the marginal revenue to the union (the additional wagesearned) is equal to the extra cost of inducing the worker to work. This involveschoosing the quantity of labor at the point where the marginal revenue curvecrosses the supply curve of labor. Note that the marginal revenue curve has twicethe slope of the labor demand curve. Marginal revenue is less than the wage,because when more workers are hired, all workers receive a lower wage.Setting the marginal revenue curve equal to the supply curve for labor, we find:1200 - 20w = 20w, or w* = 30.At w*, we may determine the number of workers who are willing to work bysubstituting w* into the labor supply equation:L * = (20)(30) = 600.Therefore, if the union wants to maximize the rent that the union members earn, theunion should limit employment to 600 members.To determine the wage the members will earn, substitute L * into the labor demandequation:600 = 1,200 - 10w , or w = 60.The total rent the employed union members will receive is equal to:Rent = (60 - 30)(600) + (0.5)(30)(600) = $27,000.Notice that the wage is higher and the number of workers employed is lower than in Exercise (8).*10. A firm uses a single input, labor, to produce output q according to the production function. The commodity sells for $150 per unit and the wage rate is $75 per hour.a. Find the profit-maximizing quantity of L.There are two (equivalent) methods of solving this problem. Most generally,define the profit function, where revenues and costs are expressed in terms of theinput, calculate the first order necessary condition (the first derivative of the profitfunction), and solve for the optimal quantity of the input. Alternatively, use therule that the firm will hire labor up until the point where the marginal revenueproduct (p*MP L ) equals the wage rate. Using the first method:π=TR -TC =pq -wLπ=150*8*L 12-75L∂π∂L=600L -12-75=0L =64.b. Find the profit-maximizing quantity of q.From part a, the profit maximizing quantity of labor is 64 so substitute thisquantity of labor into the production function to find q =8L 12=8*64=64. c. What is the maximum profit?Profit is total revenue minus total cost or π=150*64-75*64=4800.d. Suppose now that the firm is taxed $30 per unit of output and the wage rate issubsidized at a rate of $15 per hour. Assume the firm is a price taker, so that theprice of the product remains at $150. Find the new profit-maximizing levels of L, q, and profit.After the $30 tax per unit of output is paid, the firm receives 150-30=$120 per unitof output sold. This is the relevant price for the profit maximizing decision. The input cost is now 75-15=$60 per unit labor after the subsidy is received. The profit maximizing values can be found as in parts a-c above:TR-TC=pq-wLp=120*8*L12-60L¶p¶L=480L-12-60=0L=64q=64p=3840.e.Now suppose that the firm is required to pay a 20% tax on its profits. Find the newprofit-maximizing levels of L, q, and profit.The profit maximizing values can be found as in parts a-c above, only here profit is80% of total revenue minus total cost.π=.8(TR-TC)=.8(pq-wL)π=.8(150*8*L12-75L)∂π∂L=480L-12-60=0L=64q=64π=3840.。
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厂商的投入 品需求曲线
W=ME=MC
MRP
投入品的市场供应曲线
受效用递减规律的
影响，随着投入品 价格的上升，单位 收入增加给投入品 供应者带来的效用 是递减的 当工资增加到一定 程度后，愿意工作 的时间就会下降
工 资
工作时间
个人选择：闲暇~其他商品
其他 商品
原预算线
工资的增加达到一定程度，可 能会带来劳动供应的减少
第十四章 要素投入品市场
要素市场：劳动、原材料及其他生产投入品 市场 主要讨论四种要素市场：
1.
2.
3. 4.
完全竞争要素市场 要素购买者具有垄断势力的市场 要素出售者具有垄断势力的市场 要素购买者、要素出售者均具有垄断势力的市场
要素市场的均衡和产品市场的垄断势力有关
一、竞争性要素市场
具有大量生产要素出售者和大量购买者的市
S
经济租
D=MRP
S
经济租
D
刘易斯的无限供应的劳动力市场
经济租为0 W* SL
D=MR P
W*为生存工资水平
准租金
可变投入品可以自由流动，对可变投入的支
付必须等于它在其它用途能够得到的收益 不变投入品则被套牢，企业可以获得它留下 的报酬 不变投入品的报酬称为准租金，它是一种剩 余
准租金的取值
10
MRPL=P· MPL MRPL’ 市 场 15 10 100 120 150 产出品价格变化 产出品价格 不变
D
100 120 150
4、投入品的供应
（竞争性市场）
当投入品是完全竞争 状态时，厂商面临的 投入品的供应曲线是 一条水平直线，它是 投入品价格的接受者， 或它可以在不影响投 入品价格的情况下购 买它所想要的全部数 量
最初劳动力的价格W0和劳 动力的需求曲线MRP相交 于A 劳动力的价格下降为W’， X0投入的MRP大于W’，投 入品需求增加，机器设备 投资增加，MRP移动到 MRP’, 与W’相交于B AB过劳动力的长期需求曲 线 长期需求比短期需求更有 弹性
A W0 W’ B DL MRP’ MRP
Π= R（Y）- E（X）- F
R(Y) Y E(X) X = Y X – X =0 Y R(Y) E(X) Y =MRY; X =MP X; X =ME X
MRP X= MRY MP X MRP X =MEX =MCX
厂商利润最大化时对投入品数量 的选择取决于：MRPX=MCX
S C E G D 边际收益
产品
L1 L2
L
三、买方垄断势力的要素市场
完全竞争模式下，投入品购买者只能购
买很少一部分投入品，不能影响投入品 的价格 买方垄断的特征：买方垄断者面对的投 入品供应曲线是市场供应曲线，因为买 方垄断者是投入品的全部市场，它是唯 一买主 买方垄断者如果想要使用更多投入品就 提高价格，如果选择购买更少，就可以 降低价格
1 E(X) MEX= X =W(X)(1+ EX )
如果要素市场是完全竞争状态：
MEX=MCX=W（X） 要素的边际成本为要素价格 W（X）为要素供应曲线（平直） 如果要素市场存在垄断势力： MEX=MCX>W(X) W（X）供应曲线向上倾斜
厂商的投入品供应曲线
MEX 要素市场有垄 断势力
L2 L1 L0
ME SL=AE
DL MR
思考
中小民营企业信贷需求~垄 断势力强大的国有商业银行
SK
r* rc
MR K* K
DK=M RPK
MR为单位资金增加给资金提供者带来的收益
例1:假定厂商的生产函数是Q=12L-L2，L=0~6，其 中L是每天的劳动投入，Q是每天的产出。如果产出 品在竞争性市场以10美元出售，导出并画出厂商的 劳动需求曲线。当工资率为每天30美元时，厂商将 雇佣工人？60美元？ 这里的劳动力市场为竞争
场，双方都是价格的接受者，不能操控价格
工会力量不强的劳动力；煤炭；木材
1、只有一种要素是可变要素时对要素投 入品的需求
厂商的出发点是利润最大化，它必须考虑单
位要素的成本和其创造的收益 Π——利润；R（Y）——收益；Y——产量； E（X）——可变成本；X——可变要素投入 量；F——不变成本 Π= R（Y）- E（X）- F
效率损失：
SL
单位要素厂商的评 价值MRPL<社会评 价值P•MPL 单位要素厂商的边 际成本W<它为社 会创造的收益 P•MPL
W
DL = MRPL L
P.MPL
要素市场的经济租
在产品市场，经济租是 指厂商得到的超过生产 产出的最低成本的收入 在要素市场，经济租是 为生产要素支付的金额 超过要素供应者索取的 最小金额间的差额
D
L L1
在投入品的买方垄断市场，如果最低工资低于 竞争状态下的工资,高于垄断工资
ME
S W0 D
无失业
在投入品的买方垄断市场，如果最低工资高于 竞争状态下的工资
ME
S W*
D
L1 L2
劳动力的供应大于需求，失业量L1L2
四、卖方垄断势力的要素市场
投入品的出售者具有卖方垄断势力
电力公司 自来水公司 强大势力的工会 春运车票涨价:民工的“劫”
AC AVC P0 MC
准租金
G O
B
Q
Q0
如果价格下降，准租金可能不足以弥补固定成 本，企业经济利润也可能为负
移民对美国有益吗？
移民进入导致劳动力 的总供应由L1增加到 L2，工资由W1降低到 A W2 非移民劳动力总工资 W1 减少W1W2GC 资本所有者和其他非 W 2 劳动资源收入增加 W1W2EC 资本所有者和其他非 劳动资源收入增加>非 O 移民劳动力的损失
运方的“节”?
1、对工资率的垄断
劳动力市场的需求曲线是各厂商劳动的MRP
的加总。 劳动力的市场供应曲线向上倾斜 有了卖方垄断势力以后工会可以通过控制劳 动力的供应来控制工资
如果工会目标是雇佣 人数最多，选择供应 线和需求线的交点处 对应的产量。 W2 如果工会希望工资最 W3 高，选择点为单位劳 W 1 动力的价格等于单位 劳动力的收入处。 如果工会的目标是工 资总额最大，供应的 劳动量为劳工的边际 收入为0处的数量。
SL
WU W0 WNU DL DNU
DU
LU
LNU
3、劳动力市场的双边垄断
劳动力的购买方和出售方都 具有垄断势力时的情况 如果有买方垄断势力，没有 卖方垄断势力，W0，L0 W1 如果有卖方垄断势力（工会 以工资最高为目的），W1， W 2 L1 双边垄断，双方就会讨价还 W0 价，利益向何方倾斜取决于 实力和威胁的可信度， W2， L2 。
8
12 30
9
13 24
10
14 18
11
15 10
12
16 2
40 38
-
15
17
19
21
23
25
27
MEX
要素购买方具有垄 断势力时，要素市 场的均衡价格低于 完全竞争时的价格； 购买量也少于竞争 状态下的购买量。
SX
W0 W* D=MRPX X* X0
投入品市场具有买方垄断势力时的 社会福利损失
投入品个供应~边际支出
X数量 8 9 X价格 10 10.5 X成本 80 94.5 X边际成本 14.5
10
11 12 13 14
11
11.5 12 12.5 13
110
126.5 144 162.5 182
15.5
16.5 17.5 18.5 19.5
投入品的边际支出大于其价格，只有当价格增加才 能带来供应量的增加，投入品每增加一单位，全部 投入品都必须支付更高价格
闲暇
工资上升意味着闲暇价格上升，替代：减少闲暇，增加其他 商品的需求；收入：购买力增加，两种商品的需求都增加
二、竞争性要素市场的均衡
竞争性要素市场的均衡位于投入品的需求等
于投入品的供应处 在要素市场和产品市场都是竞争状态时，资 源得到有效使用
产品市场和劳动力供求市场都是竞争状 态时的劳动力供求均衡
投入X 3 4 MPX 10 9 总产出Y 33 42 PY 20 19.5 R 660 819 MRPX 159
5
6 7 8 9
8
7 6 5 4
50
57 63 68 72
19
18.5 18 17.5 17
950
1054.5 1134 1190 1224
131
104.5 79.5 56 34
当产品市场存在垄断势力时 竞争性劳动力
某投入要素（劳动力）的市场需求曲线是通
过把各产业的对该要素（劳动力）的需求曲 线水平加总得到 但要考虑投入品市场价格和产出品市场价格 的互动。
前提：劳动力的供应方和 需求方都是竞争状态；产 出品市场也是竞争状态
厂商 15
厂商： 劳动力价格15~劳动力 的需求100；劳动力的 价格10~劳动力的需求 150。当所有厂商都增 加对劳动力的投入而增 加生产，会导致产出品 价格下降，MRP曲线 的内移，与10对应的 需求为120
产出市场为完全竞争 时对投入品的需求
产出市场有垄断 势力时对投入品 的需求
MRPX=P（Y）MPX MRPX=MRYMPX
0
X的投入量
再看要素市场
E(X) MEX = X E(X)=W(X)X E(X) W( X ) X = X X+W(X)
1 =W(X)(1+ EX )