Thomas12e-Chapter2托马斯管理经济学章2

1-1©2016byMcGraw-HillEducation.Thisisproprietarymaterialsolelyforauthorizedinstructoruse.Notauthorizedforsaleordistributioninanymanner.Thisdocumentmaynotbecopied,scanned,duplicated,forwarded,distributed,orpostedonawebsite,inwholeorpart.第2章需求、供给和市场均衡©2016byMcGraw-HillEducation.Thisisproprietarymaterialsolelyforauthorizedinstructoruse.Notauthorizedforsaleordistributioninanymanner.Thisdocumentmaynotbecopied,scanned,duplicated,forwarded,distributed,orpostedonawebsite,inwholeorpart.2-2©2016byMcGraw-HillEducation.Thisisproprietarymaterialsolelyforauthorizedinstructoruse.Notauthorizedforsaleordistributioninanymanner.Thisdocumentmaynotbecopied,scanned,duplicated,forwarded,distributed,orpostedonawebsite,inwholeorpart.学习目标（2.1）认识需求函数，并能够区分需求变化与需求量变化；（2.2）认识供给函数，并能够区分供给变化与供给量变化；（2.3）解释为什么需求量等于供给量时的价格达到市场均衡；（2.4）用消费者剩余、生产者剩余和社会剩余来衡量市场交易的得益；（2.5）预测需求或供给变化时对均衡价格和均衡数量的影响；（2.6）阐述政府制定限制价与支持价的影响。2-3©2016byMcGraw-HillEducation.Thisisproprietarymaterialsolelyforauthorizedinstructoruse.Notauthorizedforsaleordistributioninanymanner.Thisdocumentmaynotbecopied,scanned,duplicated,forwarded,distributed,orpostedonawebsite,inwholeorpart.需求需求量(Qd)~在一定的时间段内，消费者愿意并且有能力购买的商品或服务的数量。2-4©2016byMcGraw-HillEducation.Thisisproprietarymaterialsolelyforauthorizedinstructoruse.Notauthorizedforsaleordistributioninanymanner.Thisdocumentmaynotbecopied,scanned,duplicated,forwarded,distributed,orpostedonawebsite,inwholeorpart.需求的影响因素影响Qd的6个变量~商品或服务的价格(P)~消费者的收入(M)~相关产品或服务的价格(PR)~消费者的偏好(T)~产品未来的预期价格(Pe)~市场上消费者的数量(N)广义需求函数Qd=f(P,M,PR,T,Pe,N)2-5©2016byMcGraw-HillEducation.Thisisproprietarymaterialsolelyforauthorizedinstructoruse.Notauthorizedforsaleordistributioninanymanner.Thisdocumentmaynotbecopied,scanned,duplicated,forwarded,distributed,orpostedonawebsite,inwholeorpart.广义需求函数b,c,d,e,f,&g是斜率参数~测度了当其他变量保持不变时，该个变量变动对Qd的影响参数的符号表示这个变量与Qd之间的关系~正号表示正向关系即正相关~负号表示反向关系即负相关Qd=a+bP+cM+dPR+eT+fPe+gN2-6©2016byMcGraw-HillEducation.Thisisproprietarymaterialsolelyforauthorizedinstructoruse.Notauthorizedforsaleordistributioninanymanner.Thisdocumentmaynotbecopied,scanned,duplicated,forwarded,distributed,orpostedonawebsite,inwholeorpart.变量与Qd的关系斜率参数的符号负相关广义需求函数对于互补品负相关PPeNMPR正相关正相关正相关对于正常品正相关对于低档品负相关对于替代品正相关b=Qd/P为负c=Qd/M为正c=Qd/M为负d=Qd/PR为正d=Qd/PR为负f=Qd/Pe为正g=Qd/N为正e=Qd/T为正T2-7©2016byMcGraw-HillEducation.Thisisproprietarymaterialsolelyforauthorizedinstructoruse.Notauthorizedforsaleordistributioninanymanner.Thisdocumentmaynotbecopied,scanned,duplicated,forwarded,distributed,orpostedonawebsite,inwholeorpart.直接需求函数直接需求函数，或简称需求，表示当其他变量保持不变时，需求量Qd与产品价格P之间的关系~Qd=f(P)需求法则~其他因素保持不变，P下降时Qd增加~其他因素标尺不变，P上升时Qd减少~Qd/P必须为负2-8©2016byMcGraw-HillEducation.Thisisproprietarymaterialsolelyforauthorizedinstructoruse.Notauthorizedforsaleordistributioninanymanner.Thisdocumentmaynotbecopied,scanned,duplicated,forwarded,distributed,orpostedonawebsite,inwholeorpart.收入对需求的影响正常品~如果其他变量不变，收入增加会增大消费者对某种产品的需求量，我们称此类产品为正常品（normalgoods）低档品~市场上有些产品或服务，当消费者的收入上升时，对它的市场需求量反而会下降，此类产品被称为低档品（inferiorgoods）2-9©2016byMcGraw-HillEducation.Thisisproprietarymaterialsolelyforauthorizedinstructoruse.Notauthorizedforsaleordistributioninanymanner.Thisdocumentmaynotbecopied,scanned,duplicated,forwarded,distributed,orpostedonawebsite,inwholeorpart.其他商品价格对需求的影响替代品~如果一种产品价格的上升会增加消费者对另一种产品的需求称这些商品为替代品，那么两种产品是替代性的互补品~在其他的条件不变时，当一种产品价格的降低，会减少消费者对其他商品的需求时，两种商品也是替代性关系2-10©2016byMcGraw-HillEducation.Thisisproprietarymaterialsolelyforauthorizedinstructoruse.Notauthorizedforsaleordistributioninanymanner.Thisdocumentmaynotbecopied,scanned,duplicated,forwarded,distributed,orpostedonawebsite,inwholeorpart.变量与需求量Qd的关系斜率参数的符号广义需求函数对于互补品负相关PPENMPR负相关正相关正相关正相关对于正常品正相关对于低档品负相关对于替代品正相关b=Qd/P为正c=Qd/M为正c=Qd/M为负d=Qd/PR为正d=Qd/PR为负f=Qd/PE为正g=Qd/N为正e=Qd/T为正T2-11©2016byMcGraw-HillEducation.Thisisproprietarymaterialsolelyforauthorizedinstructoruse.Notauthorizedforsaleordistributioninanymanner.Thisdocumentmaynotbecopied,scanned,duplicated,forwarded,distributed,orpostedonawebsite,inwholeorpart.反需求函数习惯上,将价格(P)绘在纵轴上，需求量(Qd)绘在横轴上~这种方式描绘的需求函数是反需求函数P=f(Qd)2-12©2016byMcGraw-HillEducation.Thisisproprietarymaterialsolelyforauthorizedinstructoruse.Notauthorizedforsaleordistributioninanymanner.Thisdocumentmaynotbecopied,scanned,duplicated,forwarded,distributed,orpostedonawebsite,inwholeorpart.绘制需求曲线直线需求曲线上的点表示:~给定价格下能够购买的商品的最大数量~对特定数量的商品消费者愿意支付的最高价格2-13©2016byMcGraw-HillEducation.Thisisproprietarymaterialsolelyforauthorizedinstructoruse.Notauthorizedforsaleordistributioninanymanner.Thisdocumentmaynotbecopied,scanned,duplicated,forwarded,distributed,orpostedonawebsite,inwholeorpart.需求曲线(图2.1)Qd=1,400–10P2-14©2016byMcGraw-HillEducation.Thisisproprietarymaterialsolelyforauthorizedinstructoruse.Notauthorizedforsaleordistributioninanymanner.Thisdocumentmaynotbecopied,scanned,duplicated,forwarded,distributed,orpostedonawebsite,inwholeorpart.绘制需求曲线需求量的变动~当价格变化时才发生~沿着需求曲线移动需求的变动~当其他变量或影响需求的因素发生变化时才发生~需求曲线向左或向右移动2-15©2016byMcGraw-HillEducation.Thisisproprietarymaterialsolelyforauthorizedinstructoruse.Notauthorize