英文10-垄断竞争.ppt

FourTypesofIndustries ImperfectlyCompetitiveMarkets MonopolyMonopolisticCompetitionManyfirmssellingproductsthataresimilarbutnotidentical OligopolyOnlyafewsellers eachofferingasimilaroridenticalproducttotheothers TheFourTypesofMarketStructure Monopoly Oligopoly MonopolisticCompetition PerfectCompetition TapwaterCableTV TennisballsCrudeoil NovelsMovies WheatMilk NumberofFirms TypeofProducts MonopolisticCompetition MonopolisticCompetition Marketsthathavesomefeaturesofcompetitionandsomefeaturesofmonopoly AttributesofMonopolisticCompetition ManysellersProductdifferentiationFreeentryandexit ManySellers Therearemanyfirmscompetingforthesamegroupofcustomers Productexamplesincludebooks CDs movies computergames restaurants pianolessons cookies furniture etc ProductDifferentiation Eachfirmproducesaproductthatisatleastslightlydifferentfromthoseofotherfirms Ratherthanbeingapricetaker eachfirmfacesadownward slopingdemandcurve FreeEntryorExit Firmscanenterorexitthemarketwithoutrestriction Thenumberoffirmsinthemarketadjustsuntileconomicprofitsarezero MonopolisticCompetitorsintheShortRun a FirmMakesaProfit Quantity 0 Price Demand MR ATC MC MonopolisticCompetitorsintheShortRun Quantity 0 Price Demand MR b FirmMakesLosses MC ATC MonopolisticCompetitionintheShortRun Short runeconomicprofitsencouragenewfirmstoenterthemarket This Increasesthenumberofproductsoffered Reducesdemandfacedbyfirmsalreadyinthemarket Incumbent 传统运营商 firms demandcurvesshifttotheleft Demandfortheincumbentfirms productsfall andtheirprofitsdecline MonopolisticCompetitionintheShortRun Short runeconomiclossesencouragefirmstoexitthemarket This Decreasesthenumberofproductsoffered Increasesdemandfacedbytheremainingfirms Shiftstheremainingfirms demandcurvestotheright Increasestheremainingfirms profits TheLong RunEquilibrium Firmswillenterandexituntilthefirmsaremakingexactlyzeroeconomicprofits AMonopolisticCompetitorintheLongRun zeroeconomicprofits Quantity Price 0 Demand MR ATC MC TwoCharacteristicsofLong RunEquilibrium Asinamonopoly priceexceedsmarginalcost Profitmaximizationrequiresmarginalrevenuetoequalmarginalcost Thedownward slopingdemandcurvemakesmarginalrevenuelessthanprice TwoCharacteristicsofLong RunEquilibrium Asinacompetitivemarket priceequalsaveragetotalcost Freeentryandexitdriveeconomicprofittozero MonopolisticversusPerfectCompetition Therearetwonoteworthydifferencesbetweenmonopolisticandperfectcompetition excesscapacity 超额的产能 andmarkup 加价 ExcessCapacity Thereisexcesscapacityinmonopolisticcompetitioninthelongrun Inmonopolisticcompetition outputislessthantheefficientscaleofperfectcompetition ExcessCapacity Quantity a MonopolisticallyCompetitiveFirm b PerfectlyCompetitiveFirm Quantity Price P MR demandcurve MC ATC Price Demand MC ATC P MC P ExcessCapacity Thereisnoexcesscapacityinperfectcompetitioninthelongrun Freeentryresultsincompetitivefirmsproducingatthepointwhereaveragetotalcostisminimized whichistheefficientscaleofthefirm MarkupOverMarginalCost Foracompetitivefirm priceequalsmarginalcost Foramonopolisticallycompetitivefirm priceexceedsmarginalcost MarkupOverMarginalCost Becausepriceexceedsmarginalcost anextraunitsoldatthepostedpricemeansmoreprofitforthemonopolisticallycompetitivefirm MarkupOverMarginalCost Quantity a MonopolisticallyCompetitiveFirm b PerfectlyCompetitiveFirm Quantity Price P MC P MR demandcurve MC ATC Quantityproduced Price P Demand Marginalcost MC ATC MR Quantityproduced MonopolisticversusPerfectCompetition Quantity a MonopolisticallyCompetitiveFirm b PerfectlyCompetitiveFirm Quantity Price P MR demandcurve MC ATC Quantityproduced Efficientscale Price P Demand MC ATC P MC MR Quantityproduced Efficientscale MonopolisticCompetitionandtheWelfareofSociety Monopolisticcompetitiondoesnothaveallthedesirablepropertiesofperfectcompetition MonopolisticCompetitionandtheWelfareofSociety Thereisthenormaldeadweightlossofmonopolypricinginmonopolisticcompetitioncausedbythemarkupofpriceovermarginalcost However theadministrativeburdenofregulatingthepricingofallfirmsthatproducedifferentiatedproductswouldbeoverwhelming MonopolisticCompetitionandtheWelfareofSociety Anotherwayinwhichmonopolisticcompetitionmaybesociallyinefficientisthatthenumberoffirmsinthemarketmaynotbethe ideal one ProductDifferentiation Productdifferentiation theeffortbyfirmstoproducegoodsthatareslightlydifferentfromothertypesofgoods Homogeneousproducts goodsthathavenoproductdifferentiation goodsthatareexactlythesame Advertising Whenfirmsselldifferentiatedproductsandchargepricesabovemarginalcost eachfirmhasanincentivetoadvertiseinordertoattractmorebuyerstoitsparticularproduct Advertising Firmsthatsellhighlydifferentiatedconsumergoodstypicallyspendbetween10and20percentofrevenueonadvertising Overall about2percentoftotalrevenue orover 100billionayear isspentonadvertising Advertising Criticsofadvertisingarguethatfirmsadvertiseinordertomanipulatepeople stastes Theyalsoarguethatitimpedes 阻碍 competitionbyimplyingthatproductsaremoredifferentthantheytrulyare Advertising DefendersarguethatadvertisingprovidesinformationtoconsumersTheyalsoarguethatadvertisingincreasescompetitionbyofferingagreatervarietyofproductsandprices Thewillingnessofafirmtospendadvertisingdollarscanbeasignaltoconsumersaboutthequalityoftheproductbeingoffered BrandNames Criticsarguethatbrandnamescauseconsumerstoperceivedifferencesthatdonotreallyexist HowareProductsDifferentiated Waystodifferentiateproducts PhysicalcharacteristicsAlteringtheproductsphysicalcharacteristics suchasmakingthelegroominacarlongerormakingaknifesharper LocationAMcDonald srestaurant10milesawayhasthesamemenuandthesameproductastheonedownthestreet However itismorelikelyforyoutobuyfromthenearerrestaurant 3 TimeaflightfromLosAngelestoNewYorkthatleavesat10a m isadifferentproductasonethatleavesat6p m a24hoursupermarketoffersadifferentservicefromanotherthatisn t Convenience yogurtinatube singleservingmicrowaveablesoups etc offersmoreconveniencetotheeverbusyindividual HowareProductsDifferentiated BrandNames Economistshavearguedthatbrandnamesmaybeausefulwayforconsumerstoensurethatthegoodstheyarebuyingareofhighquality providinginformationaboutquality givingfirmsincentivetomaintainhighquality Summary Amonopolisticallycompetitivemarketischaracterizedbythreeattributes manyfirms differentiatedproducts andfreeentry Theequilibr