1、PowerPoint Slides prepared by:Andreea CHIRITESCUEastern Illinois University1414竞争市场上的企业 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 passw
2、ord-protected website for classroom use.1什么是竞争市场 竞争市场(完全竞争市场)1.市场中有许多买者和卖者2.交易相同产品每个买者和卖者都是价格接受者3.企业自由进出市场 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 o
3、therwise on a password-protected website for classroom use.2什么是竞争市场 企业努力使利润最大化 利润=总收益减总成本 总收益,TR=P Q 平均收益 AR=TR/Q=P 边际收益 MR=TR/Q对于竞争企业：MR=P 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
4、a certain product or service or otherwise on a password-protected website for classroom use.3表 14 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
5、on a password-protected website for classroom use.竞争企业的总收益、平均收益和边际收益表 25 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 w
6、ebsite for classroom use.利润最大化:数字实例利润最大化 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.6图 17 2
7、015 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.竞争企业的利润最大化 Costsand收益这个图表示出了边际成本曲线MC、平均成本曲线ATC和平均
8、可变成本曲线AVC。它还表示出了市场价格P，对一个竞争企业而言，市场价格P等于边际收益MR和平均收益AR。在产量为Q1时，边际收益MR1大于边际成本MC1，因此增加产量增加了利润。在产量为Q2时，边际成本MC2大于边际收益MR2，因此减少产量增加了利润。利润最大化的产量Qmax是在水平价格线与边际成本曲线相交之处。数量 0ATCAVCP=AR=MRP=MR1=MR2MCMC1MC2Q2Q1QMAXThe firm maximizes 利润 by producing the 数量 at which marginal cost equals marginal 收益.图 58 2015 Cengag
9、e 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.用价格与平均总成本之间面积表示的利润Price价格和平均总成本之间阴影方框的面积代表企业的利润。这个方框的高是价格减平
10、均总成本（P-ATC），而方框的宽是产量Q。在(a)幅中，价格高于平均总成本，因此，企业有正利润。在(b)幅中，价格低于平均总成本，因此，企业有亏损。数量 0(a)A firm with 利润s利润 MCATCP=AR=MRPQ(利润-maximizing 数量)ATCPrice数量 0(b)A firm with 损失es损失MCATCP=AR=MRPQ(损失-minimizing 数量)ATC竞争性企业短期利润的5种情况1。PATC，02。P=ATC,=0 PATC,0，比较：，比较：不生产，则利润不生产，则利润-FC 生产生产q*，则利润，则利润PQ-TC PQ-VC-FC Q(P-AV
11、C)-FC3.AVCPATC,4.P=AVC5.PAVC,.2.butshuts down若PAVC.图 613 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 class
12、room use.短期的市场供给曲线Price在短期中，市场上企业的数量是固定的。因此，(b)幅所示的市场供给曲线，反映了(a)幅所示的单个企业的边际成本曲线。在这个有1000家企业市场上，市场供给量是1000乘以每个企业的供给量。数量(firm)0(a)Individual firm supplyMC100$2.00Price数量(market)0(b)市场供给2001.00Supply100,000$2.00200,0001.00利润最大化 企业的长期决策退出市场，如果总收益 总成本（TR TC）;或者，P ATC或者，利润ATC,.2.but exits 若PATCATC供给曲线 长期，
13、当进出过程结束时，仍然在市场中的企业获得零利润(P=ATC)因为 MC=ATC:有效规模 长期，市场供给曲线完全弹性ATC最低水平部分 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 websit
14、e for classroom use.16图 717 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.长期市场供给Price长期中，企业将进入
15、或退出市场，直至利润变为零。因此，价格等于最低平均成本，如(a)幅所示。企业数量自发调整，以保证在这种价格时所有需求都得到满足。长期市场供给曲线在这种价格时是水平的，如(b)幅所示。数量(firm)0(a)Firms Zero-利润 ConditionMCATCPrice数量(market)0(b)市场供给P=minimumATCSupply图 818 2015 Cengage Learning.All Rights Reserved.May not be copied,scanned,or duplicated,in whole or in part,except for use as pe
16、rmitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.短期和长期内的需求增加短期和长期内的需求增加 市场开始时处于长期均衡，如（a）幅中A点所示。在这种均衡时，每个企业获得零利润，而且，价格等于最低平均总成本。（b）幅表示当需求从D1增加到D2时短期中发生的变动。均衡从P1上升为P2，市场销售量从Q1增加到Q2。由于价格现在高于平均总成本，企业盈利，在某一时期内鼓励新的企业进入市场。这种进入
17、使短期供给曲线从S1向右移动到S2，如（c）幅所示。在新的长期均衡，即C点时，价格回到P1，但销售量增加到Q3。利润再次为零，价格回到最低平均总成本，但市场上有更多的企业来满足更大的需求。供给曲线 长期供给曲线 可能向右上方倾斜一些用于生产的资源数量可能是有限的企业可能会面临不同成本一些企业可能会在长期中仍获得利润 长期供给曲线比短期供给曲线更富有弹性 2015 Cengage Learning.All Rights Reserved.May not be copied,scanned,or duplicated,in whole or in part,except for use as pe
18、rmitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.20供给曲线 如果竞争企业利润为零，为什么它们要留在市场上 利润=总收益 总成本总成本包括所有机会成本零利润 均衡经济利润为零会计利润是正的 2015 Cengage Learning.All Rights Reserved.May not be copied,scanned,or duplicated,in whole or in pa
19、rt,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.21“我们是“非营利”组织！我们无意为之，但我们确实是。”讨论厂商的目标生意冷清的餐馆和淡季的小型高尔夫球场 餐馆 午餐时持续营业?固定成本 不相干 短期中作为沉没成本可变成本 相关停产，若午餐收入 可变成本23 2015 Cengage Learning.All Rights Reserve
20、d.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.即使许多桌子都空着，照常营业仍然是有利可图的。生意冷清的餐馆和淡季的小型高尔夫球场 小型高尔夫球场的管理者忽略固定成本停产 若 收益 可变成本24 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.
