微观经济学之利润最大化和竞争性供给.pptx
- 文档编号:18818262
- 上传时间:2023-12-12
- 格式:PPTX
- 页数:83
- 大小:690.62KB
微观经济学之利润最大化和竞争性供给.pptx
《微观经济学之利润最大化和竞争性供给.pptx》由会员分享,可在线阅读,更多相关《微观经济学之利润最大化和竞争性供给.pptx(83页珍藏版)》请在冰点文库上搜索。
,第八章利润最大化和竞争性供给,本章概要,完全竞争市场的利润最大化以及短期、长期均衡,1,假设:
厂商追求利润最大化,不符合三条件,定义:
完全竞争市场,分析框架:
结论短期供给线;三种长期供给线,经验研究,符合三条件,竞争市场利润最大化与均衡,短期均衡:
短期供给线、生产者剩余,长期均衡:
长期供给线,长期利润最大化受冲击:
税收效应,2,1.1厂商追求利润最大化的假设,3,2.1完全竞争市场的定义,符合下面三个特征的市场称为完全竞争市场:
(1)产品同质(Producthomogeneity);
(2)厂商和消费者都是价格接受者(Pricetaking);(3)厂商无成本进入与退出(Freeentryandexit),4,Industry,D,$4,S,
(1)产品同质:
存在市场均衡价格P,5,Firm,Industry,D,$4,S,6,Firm,AVCi,AVCj,7,Firm,2.2完全竞争市场的重要性质,8,证明,9,3.1.分析框架:
数学解,10,q2,MC,q*,AR=MR=P,A,q1:
MRMCq2:
MCMRq*:
MC=MR,q1,LostProfitforq2q*,LostProfitforq2q*,3.2.分析框架:
几何解,11,当MRMC时增加产量所增加的收益大于所增加的成本,因而总利润可以增加;当MRMC时减少产量所减少的收益小于所减少的成本,因而总利润可以增加;当MR=MC时无论怎样调整产量,总利润都只会减少而不会增加。
12,MC,AVC,AC,q*,AR=MR=P,A,4.1.短期均衡MR=MC,情形1:
利润为正,13,MC,AVC,AC,q*,AR=MR=P,A,情形2:
利润为0,14,MC,AVC,AC,q*,AR=MR=P,A,情形3:
弥补全部可变成本之外还能弥补部分固定成本,15,MC,AVC,AC,q*,AR=MR=P,A,情形4:
刚好弥补全部可变成本,不能弥补一点固定成本,16,MC,AVC,AC,q*,AR=MR=P,A,情形5:
甚至不能弥补全部可变成本,更谈不上弥补一点固定成本,17,关于短期均衡的总结,短期均衡的条件是:
SMC=SMR=P短期均衡中利润可能为正,为零,为负。
18,Price($perunit),Output,MC,P=AVC,S,4.2.1由短期均衡的五种情形可推导出完全竞争厂商的短期供给线:
几何,19,4.2.2由短期均衡的五种情形可推导出完全竞争厂商的短期供给线:
数学,20,ProducerSurplus,Price($perunitofoutput),Output,AVC,MC,q*,4.3.1由短期条件理解生产者剩余的定义:
几何,C,D,21,4.3.2由短期条件理解生产者剩余的定义:
数学,22,生产者剩余与经济利润的区别,23,D,ProducerSurplus,Price($perunitofoutput),Output,S,市场的生产者剩余,24,q1,Price,Output,q3,LAC,LMC,4.4.1从长期利润最大化到长期均衡,25,Price,Output,q3,LAC,LMC,4.4.2从长期利润最大化到长期均衡,26,4.5行业的长期供给曲线,27,q1,D1,S1,Q1,P1,D2,P2,S2,Q2,Output,Output,$,$,P1,SL,
(1)成本不变行业,28,Output,Output,$,$,D1,S1,q1,P1,SL,P3,S2,P3,Q3,D2,Q2,P2,
(2)成本递增行业,29,S2,SL,P3,Output,Output,$,$,P1,D1,S1,q1,D2,(3)成本递减行业,30,Price($perunitofoutput),Output,t,MC2=MC1+tax,AVC2,4.5长期利润最大化受到税收冲击的情形,q2,31,32,TheSverigesRiksbankPrizeinEconomicSciencesinMemoryofAlfredNobel2009,ElinorOstrom1/2USAIndianaUniversityBloomington,IN,USAb.1933,forheranalysisofeconomicgovernance,especiallythecommons,33,TheSverigesRiksbankPrizeinEconomicSciencesinMemoryofAlfredNobel2009,OliverE.Williamson1/2USAUniversityofCaliforniaBerkeley,CA,USAb.1932,forhisanalysisofeconomicgovernance,especiallytheboundariesofthefirm,34,35,Economicgovernance:
theorganizationofcooperationElinorOstromhasdemonstratedhowcommonpropertycanbesuccessfullymanagedbyuserassociations.,PressRelease12October2009,36,OliverWilliamsonhasdevelopedatheorywherebusinessfirmsserveasstructuresforconflictresolution.,37,Overthelastthreedecadestheseseminalcontributionshaveadvancedeconomicgovernanceresearchfromthefringetotheforefrontofscientificattention.,38,Economictransactionstakeplacenotonlyinmarkets,butalsowithinfirms,associations,households,andagencies.Whereaseconomictheoryhascomprehensivelyilluminatedthevirtuesandlimitationsofmarkets,ithastraditionallypaidlessattentiontootherinstitutionalarrangements.,39,TheresearchofElinorOstromandOliverWilliamsondemonstratesthateconomicanalysiscanshedlightonmostformsofsocialorganization.,40,ElinorOstromhaschallengedtheconventionalwisdomthatcommonpropertyispoorlymanagedandshouldbeeitherregulatedbycentralauthoritiesorprivatized.Basedonnumerousstudiesofuser-managedfishstocks,pastures,woods,lakes,andgroundwaterbasins,Ostromconcludesthattheoutcomesare,moreoftenthannot,betterthanpredictedbystandardtheories.,41,Sheobservesthatresourceusersfrequentlydevelopsophisticatedmechanismsfordecision-makingandruleenforcementtohandleconflictsofinterest,andshecharacterizestherulesthatpromotesuccessfuloutcomes.,42,OliverWilliamsonhasarguedthatmarketsandhierarchicalorganizations,suchasfirms,representalternativegovernancestructureswhichdifferintheirapproachestoresolvingconflictsofinterest.,43,Thedrawbackofmarketsisthattheyoftenentailhagglinganddisagreement.Thedrawbackoffirmsisthatauthority,whichmitigatescontention,canbeabused.Competitivemarketsworkrelativelywellbecausebuyersandsellerscanturntoothertradingpartnersincaseofdissent.,44,Butwhenmarketcompetitionislimited,firmsarebettersuitedforconflictresolutionthanmarkets.AkeypredictionofWilliamsonstheory,whichhasalsobeensupportedempirically,isthereforethatthepropensityofeconomicagentstoconducttheirtransactionsinsidetheboundariesofafirmincreasesalongwiththerelationship-specificfeaturesoftheirassets.,45,ElinorOstromdeliveringalectureatIndianaUniversity,Bloomington,July2008.,46,例题1,47,48,49,50,例题2,51,52,例题3,53,54,例题3,55,56,例题4,57,58,例题5,Supposeyouaregiventhefollowinginformationaboutaparticularindustry:
Assumethatallfirmsareidentical,andthatthemarketischaracterizedbypurecompetition.,59,例题5,
(1)Findtheequilibriumprice,theequilibriumquantity,theoutputsuppliedbythefirm,andtheprofitofthefirm.,60,61,
(2)Wouldyouexpecttoseeentryintoorexitfromtheindustryinthelong-run?
Explain.Whateffectwillentryorexithaveonmarketequilibrium?
62,
(2)解:
Entrybecausethefirmsintheindustryaremakingpositiveprofit.Asfirmsenter,thesupplycurvefortheindustrywillshiftdownandtotherightandtheequilibriumpricewillfall,allelsethesame.Thiswillreduceeachfirmsprofitdowntozerountilthereisnoincentiveforfurtherentry.,63,(3)Whatisthelowestpriceatwhicheachfirmwouldsellitsoutputinthelongrun?
Isprofitpositive,negative,orzeroatthisprice?
Explain.,64,65,(4)错题目Whatisthelowestpriceatwhicheachfirmwouldsellitsoutputintheshortrun?
Isprofitpositive,negative,orzeroatthisprice?
Explain.,66,67,例题6,68,69,例题7,70,71,例题8,Consideracitythathasanumberofhotdogsstandsoperatingthroughoutthedowntownarea.Supposethateachvendorhasamarginalcostof$1.50perhotdogsold,andnofixedcost.Supposethemaximumnumberofhotdogsanyonevendorcansellinadayis100.,72,
(1)Ifthepriceofahotdogis$2,howmayhotdogsdoeseachvendorwanttosell?
Sincemarginalcostisequalto1.5andthepriceisequalto2,thehotdogvendorwillwanttosellasmanyhotdogsaspossible,orinotherwords,100hotdogs.,73,
(2)Iftheindustryisperfectlycompetitivewillthepriceremainat$2forahotdog?
Ifnot,whatwillthepricebe?
Thepriceshouldfallto$1.50sothatpriceisequaltomarginalcost.Eachhotdogvendorwillhaveanincentivetolowerthepriceofahotdogbelow$2sotheycansellmorehotdogsthantheircompetitors.Nohotdogvendorwillsellahotdogforapricebelowmarginalcost,sothepricewillfalluntilitreaches$1.50.,74,(3)Ifeachvendorsellsexactly100hotdogsadayandthedemandforhotdogsfromvendorsinthecityisQ=4400-1200P,howmanyvendorsarethere?
Ifpriceis1.50thenQ=4400-1200*1.5=2600intotal.Ifeachvendorsells100hotdogsthenthereare26vendors.,75,(4)Supposethecitydecidestoregulatehotdogvendorsbyissuingpermits.Ifthecityissuesonly20permits,andifeachvendorcontinuestosell100hotdogsaday,whatpricewillahotdogsellfor?
Ifthereare20vendorsselling100hotdogseachthenthetotalnumbersoldis2000.IfQ=2000thenP=$2,fromthedemandcurve.,76,(5)Supposethecitydecidedtosellthepermits.Whatisthehighestpriceavendorwouldpayforapermit?
Atthenewpriceof$2perhotdogthevendorismakingaprofitof$0.50perhotdog,oratotalof$50.Thisisthemosttheywouldpayonaperdaybasis.,77,例题9,Asalestaxof$1perunitofoutputisplacedononefirmwhoseproductsellsfor$5inacompetitiveindustry.,78,
(1)Howwillthistaxaffectthecostcurvesforthefirm?
Withtheimpositionofa$1taxonasinglefirm,allitscostcurvesshiftupby$1.TotalcostbecomesTC+tq,orTC+qsincet=1.AveragecostisnowAC+1.MarginalcostisnowMC+1.,79,
(2)Whatwillhappentothefirmsprice,output,andprofit?
Sincethefirmisaprice-takerinacompetitivemarket,theimpositionofthetaxononlyonefirmdoesnotchangethemarketprice.Sincethefirmsshort-runsupplycurveisitsmarginalcostcurveaboveaveragevariablecostandthatmarginalcostcurvehasshiftedup(inward),thefirmsupplieslesstothemarketateveryprice.Profitsarelowerateveryquantity.,80,(3)Willtherebeentryorexitintheindustry?
Ifthetaxisplacedonasinglefirm,thatfirmwillgooutofbusiness.,81,82,83,
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 微观经济学 利润 最大化 竞争性 供给