第七版微观经济学_第4章 供给与需求的市场力量

1、.,供给与需求的市场力量, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,1,.,市场与竞争,供给与需求 经济学家们最常使用的词

2、汇 使市场经济运行的力量 买者与卖者行为，以及他们相互之间的影响, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,2,.,市场与

3、竞争,市场 由某种商品或服务的买者与卖者组成的一个群体 买方群体 决定产品的需求 卖方群体 决定产品的供给, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for c

4、lassroom use.,3,.,市场与竞争,市场采取多种形式 市场组织健全 许多农产品市场 并没有什么组织 某镇上冰淇淋市场, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected we

5、bsite for classroom use.,4,.,市场与竞争,竞争市场 市场中有许多买者和许多卖者 每一个对市场价格的影响可以忽略不计 价格和数量由买卖双方决定 它们在市场上相互作用, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or other

6、wise on a password-protected website for classroom use.,5,.,市场与竞争,完全竞争市场 提供出售的货物都是完全相同的 买者和卖者是如此众多 买方或卖方对市场价格有任何影响 价格接受者 市场价格 买者可以购买他们想要的一切 卖者可以出售他们想出售的一切, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a lic

7、ense distributed with a certain product or service or otherwise on a password-protected website for classroom use.,6,.,市场与竞争,垄断 市场上唯一的卖方 价格的决定 其他的市场 在完全竞争与垄断之间, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in

8、a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,7,.,需求,需求量 买者愿意并且能够购买一种物品的数量 需求法则 其他条件不变 当一种商品的价格上升时，商品的需求数量下降的观点 当价格下降时，需求量上升, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or i

9、n part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,8,.,需求,需求 一种商品的价格和需求量之间的关系 需求表：是一张表 需求曲线：是一张图 价格在垂直轴 水平轴的数量 个人需求 个人对产品的需求, 2015 Cengage Learning. All Rights Reserved. May not be copied, sca

10、nned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,9,.,图 1, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or

11、 in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,Catherine需求曲线和需求曲线,需求表是显示每个价格水平下的需求量的表。根据需求表画出需求曲线图表示一种物品的需求量如何随其价格变动而变动。较低的价格增加了需求量，因此需求曲线向下倾斜。,10,.,需求,市场需求 为一种商品或服务的所有个人需求总和 市场需求曲线 水平的个

12、体需求曲线 一种商品的总需求量的变化 商品价格各不一样 其他条件不变, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,11,.,

13、图 2, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,作为个人需求之和的市场需求,一个市场的需求量是所有买者在每一价格水平下水

14、平下的需求量总和。因此，可以通过把个人需求曲线水平相加而得出市场需求曲线。在价格2美元时，Catherine的需求量是4个冰淇淋蛋卷，Nicholas的需求量是3个冰淇淋蛋卷。在这一价格水平下，在市场上的需求量是7个冰淇淋蛋卷。,12,.,图 2, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain

15、 product or service or otherwise on a password-protected website for classroom use.,作为个人需求之和的市场需求,Catherine的需求,Nicholas的需求,+,=,市场需求,13,.,需求,需求曲线的移动 需求量的上升 每一价格水平下的变化，增加的的数量 需求曲线向右移动 需求量的减少 每一价格水平下的变化要减少需求量的数量 需求曲线向左移动, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplic

16、ated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,14,.,图 3, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, exce

17、pt for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,需求曲线的移动,既定价格水平下，任何使买者想购买的数量都增加的变动都会使需求曲线向右移动。既定价格水平下，任何使买者想购买的数量都减少的变动都会使需求曲线向左移动。,15,.,需求,可以改变需求曲线的变量 收入 相关物品价格 爱好 预期 买者数量, 2015 Cengage Learning. All R

18、ights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,16,.,需求,收入 正常品 其他条件不变 收入的增加导致了需求的增加 低档品 其他条件不变 收入的增加导致需求的减少, 2015 Cen

19、gage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,17,.,需求,相关物品价格 替代品，两种物品 一种物品价格的上升 导致另一种物品需求增加 互补品

20、，两种物品 一种物品价格的上升 导致另一种物品需求减少, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,18,.,需求,爱好 爱

21、好变化：改变需求 对未来的预期 预期收入增加 增加目前的需求 期待更高的价格 增加目前的需求 买者数量，增加 市场需求增加, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected websi

22、te for classroom use.,19,.,表 1, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,影响买者的变量,这

23、张表列出了可以影响消费者选择购买多少某种物品的变量。要注意的是价格所起的特殊作用：价格变动表现为沿着需求曲线的变动，而其他任何一个变量的变动将使需求曲线移动。,20,.,减少香烟需求的两种方法,使香烟和其他烟草产品的需求曲线移动 试着提高香烟的价格, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certai

24、n product or service or otherwise on a password-protected website for classroom use.,21,“什么是制止这种行为 最好的方法？”,.,减少香烟需求的两种方法,香烟和其他烟草产品的需求曲线的移动 公共服务公告 香烟包装上的强制性健康警告 在电视上禁止吸烟广告 若成功 需求曲线向左移动, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except

25、for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,22,.,减少香烟需求的两种方法,试着提高香烟的价格 对制造商征税：更高的价格 沿需求曲线运动 10% 价格 4% 吸烟量 青少年: 10% 价格 12% 吸烟量 对香烟需求与大麻需求 互补品, 2015 Cengage Learning. All Rights Reserved. May not be cop

26、ied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,23,.,图 4, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in

27、 whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,需求曲线移动与沿着需求曲线的变动,(a) 需求曲线的转变,24,如果香烟包装上的警示能说服吸烟者少吸烟，那么香烟的需求曲线就向左边移动。在（a）幅中，需求曲线从D1移动到D2。在价格为每包2美元时，需求量由每天20支减少到10支，如图中从A点到B点所示。与此相

28、比，如果税收提高香烟的价格，需求曲线没有移动，而是变动到其上另一点。在（b）幅中，当价格从2美元上升到4美元，需求量从每天20支烟减少到12支烟，如图中是从A点移动到C点所示。,.,供给,供给量 卖方愿意并且能够出售的 一个物品的数量 供给法则 其他条件不变 当一个物品的价格上升时，供给的数量也上升了 当价格下跌时，供给量下降, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitte

29、d in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,25,.,供给,供给 商品的价格和供给量之间的关系 供给表：是一张表 供给曲线：是一张图 价格在纵轴 水平轴是供给的数量 个人供给 卖方个人的供给, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or i

30、n part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,26,.,图 5, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permi

31、tted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,Ben的供给计划和供给曲线,供给表是显示在每一个价格水平下的供给量的表格。根据供给表画出供给曲线图表示一种物品的供给量如何随其价格变动而变动。由于价格越高，供给量越多，所以，供给曲线向右上方倾斜。,27,.,供给,市场供给 为一种商品或服务所有卖方的供给量总和 市场供给曲线 个人供给曲线的水平总和 一种商品的总供给量的变化 商品的价格各不一样

32、 影响供给者出售的所有其他因素都保持不变, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,28,.,图 6, 2015 Ceng

33、age Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,市场供给作为个人用品的总和,市场供给量是在每种价格水平下所有卖者的供给量之和。因此，可以通过水平地相

34、加个人供给曲线的出市场供给曲线。在价格为2美元时，Ben供给3个冰淇淋蛋卷，而Jerry供给4个冰淇淋蛋卷。在这一价格水平下，市场供给量是7个冰淇淋蛋卷。,29,.,图 6, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a

35、 password-protected website for classroom use.,市场供给作为个人用品的总和,本的供给,杰瑞的供给,+,=,市场供给,30,.,供给,供给变动 供给增加 每一价格水平下供给数量增加的任何一种变化 供给曲线向右移动 供给减少 每一价格水平下供给数量减少的任何一种变化 供给曲线向左移动, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted

36、 in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,31,.,图 7, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with

37、a certain product or service or otherwise on a password-protected website for classroom use.,供给曲线的变化,使任何既定价格水平下卖者愿意生产的数量都增加的任何一种变动，都会使供给曲线向右移动。使任何既定价格水平下卖者愿意生产的数量都减少的任何一种变动，都会使供给曲线向左移动。,32,.,供给,能改变供给曲线的变量 投入品价格 技术 预期 卖者的数量, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or d

38、uplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,33,.,供给,投入品价格 供给与投入品价格呈负相关 价格上升：使供给减少 技术 技术进步：使供给增加, 2015 Cengage Learning. All Rights Reserved. May not be copied, s

39、canned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,34,.,供给,关于未来的预期 影响现在的供给 预期价格上升 减少现在的供给 卖者数量，增加 市场供给增加, 2015 Cengage Learning. All Rights Reserved. May no

40、t be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,35,.,表 2, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplic

41、ated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,影响卖者的变量,该表列出了可以影响生产者选择出售多少某种物品的变量。要注意价格所起的特殊作用：价格变动表现为沿着供给曲线的变动，而其他任何一个变量的变动都将使供给曲线移动。,36,.,供给与需求的结合,均衡 各种力量达到平衡 一种市场价格已经达

42、到的水平 供给量=需求量 供需曲线相交, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,37,.,供给与需求的结合,均衡价格 供

43、给量和需求量 市场出清价格 均衡数量 均衡价格的供给量和需求量, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,38,.,图 8

44、, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,供给与需求的均衡,均衡出现在供给和需求曲线相交的那一点。在均衡价格时，供给量等

45、于需求量。这里的均衡价格是2美元：在这一价格水平下，供给量是7个冰淇淋蛋卷，需求量也是7个冰淇淋蛋卷。,39,.,供给与需求的结合,剩余 供给量需求量 供给过剩 价格下降的压力 沿着需求和供给曲线运动 需求量的增加 供给减少, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or

46、 service or otherwise on a password-protected website for classroom use.,40,.,供给与需求的结合,短缺 供给量供给量 超额需求 价格上升压力 沿着需求和供给曲线运动 减少需求量 供给量的增加, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with

47、 a certain product or service or otherwise on a password-protected website for classroom use.,41,.,图 9, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service o

48、r otherwise on a password-protected website for classroom use.,市场不处于均衡时,(a) 供给过量,42,在（a）幅中，存在着剩余。因为2.5美元的市场价格高于均衡价格，供给量（10个）超过需求量（4个）。供给商试图通过削减冰淇淋蛋卷的价格来增加销售量，这将会使价格向均衡水平移动。在（b）幅中，存在短缺。因为1.5美元的市场价格低于均衡价格，需求量（10个）超过供给量（4个）。由于太多的买者在追逐太少的商品，供给商可以通过提高价格来利用这一优势。因此，在这两种情况下，价格调整移动市场对供需平衡,.,供给与需求的结合,供给与需求法则

49、任何商品的价格调整 使供给量和需求量的数量要达到平衡 大多数市场中 盈余和短缺是暂时的, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom u

50、se.,43,.,供给与需求的结合,分析平衡变化的三个步骤 决定事件是否在某些情况下，改变供给曲线，需求曲线，或在某些情况下，这两个曲线 决定曲线向右或向左移动 使用供求关系图 比较初始和新的均衡 均衡价格和数量的影响, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or se

51、rvice or otherwise on a password-protected website for classroom use.,44,.,供给与需求的结合,由于需求的变动市场均衡的变化 夏天，很热的天气 冰淇淋市场的影响？ 热天气：改变需求曲线（爱好） 需求曲线向右边移动 均衡价格；均衡数量, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a licen

52、se distributed with a certain product or service or otherwise on a password-protected website for classroom use.,45,.,图 10, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain

53、product or service or otherwise on a password-protected website for classroom use.,需求增长如何影响均衡,使任何一种既定价格水平下需求量增加的事件使需求曲线向右移动。均衡价格与均衡数量都上升了。在本例中，异常炎热的夏季使买者需要更多的冰淇淋。需求曲线从D1移动到D2，导致均衡价格从2美元上升到2.5美元，均衡数量从7个上升到10个。,46,.,供给与需求的结合,沿曲线移动与运动 供给曲线的变动 供给变化 沿固定供给曲线变动 供给量的变化 需求曲线移动 需求变化 沿固定需求曲线变动 需求量的变化, 2015 Cen

54、gage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,47,.,供给与需求的结合,供给变动引起的市场均衡变化 在一个夏天，一场飓风摧毁了一部分甘蔗作物：

55、更高的糖价格 冰淇淋市场的影响？ 糖的价格变化：供给曲线 供给曲线：向左移动 均衡价格；均衡量, 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.,48,.,图 11, 2015 Cengage Learning. All Rights Res