壟斷曼昆經濟學原理第七版

Monopoly?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.1WhyMonopoliesAriseMarketpowerAlterstherelationshipbetweenafirm’scostsandthesellingpriceMonopolyChargesapricethatexceedsmarginalcostAhighpricereducesthequantitypurchasedOutcome:oftennotthebestforsociety?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.2WhyMonopoliesAriseGovernmentsCansometimesimprovemarketoutcomeMonopolyFirmthatisthesolesellerofaproductwithoutclosesubstitutesPricemakerCause:barrierstoentry?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.3WhyMonopoliesAriseBarrierstoentryAmonopolyremainstheonlysellerinthemarketBecauseotherfirmscannotenterthemarketandcompetewithitMonopolyresourcesGovernmentregulationTheproductionprocess?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.4WhyMonopoliesAriseMonopolyresourcesAkeyresourcerequiredforproductionisownedbyasinglefirmHigherprice?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.5“Ratherthanamonopoly,weliketoconsiderourselves‘theonlygameintown.’”WhyMonopoliesAriseGovernmentregulationGovernmentgivesasinglefirmtheexclusiverighttoproducesomegoodorserviceGovernment-createdmonopoliesPatentandcopyrightlawsHigherpricesHigherprofits?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.6WhyMonopoliesAriseNaturalmonopolyAsinglefirmcansupplyagoodorservicetoanentiremarketAtasmallercostthancouldtwoormorefirmsEconomiesofscaleovertherelevantrangeofoutputClubgoodsExcludablebutnotrivalinconsumption?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.7Figure18?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.EconomiesofScaleasaCauseofMonopolyCostsWhenafirm’saverage-total-costcurvecontinuallydeclines,thefirmhaswhatiscalledanaturalmonopoly.Inthiscase,whenproductionisdividedamongmorefirms,eachfirmproducesless,andaveragetotalcostrises.Asaresult,asinglefirmcanproduceanygivenamountattheleastcostQuantityofoutput0AveragetotalcostProductionandPricingDecisionsMonopolyPricemakerSoleproducerDownwardslopingdemand:themarketdemandcurveCompetitivefirmPricetakerOneproducerofmanyDemandisahorizontalline(Price)?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.9Figure210?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.DemandCurvesforCompetitiveandMonopolyFirmsPriceBecausecompetitivefirmsarepricetakers,theyineffectfacehorizontaldemandcurves,asinpanel(a).Becauseamonopolyfirmisthesoleproducerinitsmarket,itfacesthedownward-slopingmarketdemandcurve,asinpanel(b).Asaresult,themonopolyhastoacceptalowerpriceifitwantstosellmoreoutput.Quantityofoutput0(a)ACompetitiveFirm’sDemandCurvePriceQuantityofoutput0(b)AMonopolist’sDemandCurveDemandDemandProductionandPricingDecisionsAmonopoly’stotalrevenueTotalrevenue=pricetimesquantityAmonopoly’saveragerevenueRevenueperunitsoldTotalrevenuedividedbyquantityAlwaysequalstheprice?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.11ProductionandPricingDecisionsAmonopoly’smarginalrevenueRevenuepereachadditionalunitofoutputChangeintotalrevenuewhenoutputincreasesby1unitMR<PDownward-slopingdemandToincreasetheamountsold,amonopolyfirmmustlowerthepriceitchargestoallcustomersCanbenegative?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.12Table113?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.AMonopoly’sTotal,Average,andMarginalRevenueProductionandPricingDecisionsIncreaseinquantitysoldOutputeffectQishigher:increasetotalrevenuePriceeffectPislower:decreasetotalrevenueBecauseMR<PMarginal-revenuecurveisbelowthedemandcurve?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.14Figure315?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.DemandandMarginal-RevenueCurvesforaMonopolyPrice21-1-2-3543678910$11-4Thedemandcurveshowshowthequantityaffectsthepriceofthegood.Themarginal-revenuecurveshowshowthefirm’srevenuechangeswhenthequantityincreasesby1unit.Becausethepriceonallunitssoldmustfallifthemonopolyincreasesproduction,marginalrevenueisalwayslessthantheprice.Quantityofwater012345678Demand(averagerevenue)MarginalrevenueProductionandPricingDecisionsProfitmaximizationIfMR>MC:increaseproductionIfMC>MR:producelessMaximizeprofitProducequantitywhereMR=MCIntersectionofthemarginal-revenuecurveandthemarginal-costcurvePrice:onthedemandcurve?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.16Figure417?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.ProfitMaximizationforaMonopolyCostsandRevenueAmonopolymaximizesprofitbychoosingthequantityatwhichmarginalrevenueequalsmarginalcost(pointA).Itthenusesthedemandcurvetofindthepricethatwillinduceconsumerstobuythatquantity(pointB).Quantity0AveragetotalcostDemandMarginalrevenueMarginalcostQMAXBMonopolypriceA1.Theintersectionofthemarginal-revenuecurveandthemarginal-costcurvedeterminestheprofit-maximizingquantity...2....andthenthedemandcurveshowsthepriceconsistentwiththisquantity.Q1Q2ProductionandPricingDecisionsProfitmaximizationPerfectcompetition:P=MR=MCPriceequalsmarginalcostMonopoly:P>MR=MCPriceexceedsmarginalcostAmonopoly’sprofitProfit=TR–TC=(P–ATC)?Q?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.18Figure519?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.TheMonopolist’sProfitCostsandRevenueTheareaoftheboxBCDEequalstheprofitofthemonopolyfirm.Theheightofthebox(BC)ispriceminusaveragetotalcost,whichequalsprofitperunitsold.Thewidthofthebox(DC)isthenumberofunitssold.Quantity0DemandBEDMarginalrevenueQMAXAveragetotalcostMarginalcostMonopolypriceCMonopolyprofitAveragetotalcostMonopolyDrugsversusGenericDrugsMarketforpharmaceuticaldrugsNewdrug,patentlaws,monopolyProduceQwhereMR=MCP>MCGenericdrugs:competitivemarketProduceQwhereMR=MCAndP=MCPriceofthecompetitivelyproducedgenericdrugBelowthemonopolist’sprice?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.20Figure621?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.TheMarketforDrugsCostsandRevenueWhenapatentgivesafirmamonopolyoverthesaleofadrug,thefirmchargesthemonopolyprice,whichiswellabovethemarginalcostofmakingthedrug.Whenthepatentonadrugrunsout,newfirmsenterthemarket,makingitmorecompetitive.Asaresult,thepricefallsfromthemonopolypricetomarginalcost.Quantity0DemandMarginalrevenueMonopolyquantityPriceduringpatentlifeMarginalcostPriceafterpatentexpiresCompetitivequantityTheWelfareCostofMonopoliesTotalsurplusEconomicwell-beingofbuyersandsellersinamarketSumofconsumersurplusandproducersurplusConsumersurplusConsumers’willingnesstopayforagoodMinustheamounttheyactuallypayforit?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.22TheWelfareCostofMonopoliesProducersurplusAmountproducersreceiveforagoodMinustheircostsofproducingitBenevolentplanner:maximizetotalsurplusSociallyefficientoutcomeProducequantitywhereMarginalcostcurveintersectsdemandcurveChargeP=MC?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.23Figure724?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.TheEfficientLevelofOutputCostsandRevenueAbenevolentsocialplannermaximizestotalsurplusinthemarketbychoosingthelevelofoutputwherethedemandcurveandmarginal-costcurveintersect.Belowthislevel,thevalueofthegoodtothemarginalbuyer(asreflectedinthedemandcurve)exceedsthemarginalcostofmakingthegood.Abovethislevel,thevaluetothemarginalbuyerislessthanmarginalcost.Quantity0Demand(valuetobuyers)EfficientquantityMarginalcostValuetobuyersValuetobuyersCosttomonopolistCosttomonopolistValuetobuyersisgreaterthancosttosellersValuetobuyersislessthancosttosellersTheWelfareCostofMonopoliesMonopolyProducequantitywhereMC=MRProduceslessthanthesociallyefficientquantityofoutputChargeP>MCDeadweightlossTrianglebetweenthedemandcurveandMCcurve?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.25Figure826?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.TheInefficiencyofMonopolyCostsandRevenueBecauseamonopolychargesapriceabovemarginalcost,notallconsumerswhovaluethegoodatmorethanitscostbuyit.Thus,thequantityproducedandsoldbyamonopolyisbelowthesociallyefficientlevel.Thedeadweightlossisrepresentedbytheareaofthetrianglebetweenthedemandcurve(whichreflectsthevalueofthegoodtoconsumers)andthemarginal-costcurve(whichreflectsthecostsofthemonopolyproducer).Quantity0DemandMarginalrevenueMonopolyquantityMarginalcostMonopolypriceEfficientquantityDeadweightlossTheWelfareCostofMonopoliesThemonopoly’sprofit:asocialcost?Monopoly-higherprofitNotareductionofeconomicwelfareBiggerproducersurplusSmallerconsumersurplusNotasocialproblemSocialloss=DeadweightlossFromtheinefficientlylowquantityofoutput?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.27PriceDiscriminationPricediscriminationBusinesspracticeSellthesamegoodatdifferentpricestodifferentcustomersRationalstrategytoincreaseprofitRequirestheabilitytoseparatecustomersaccordingtotheirwillingnesstopayCanraiseeconomicwelfare?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.28PriceDiscriminationPerfectpricediscriminationChargeeachcustomeradifferentpriceExactlyhisorherwillingnesstopayMonopolyfirmgetstheentiresurplus(Profit)Nodeadweightloss?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.29PriceDiscriminationWithoutpricediscriminationSingleprice>MCConsumersurplusProducersurplus(Profit)Deadweightloss?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.30Figure931?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.WelfarewithandwithoutPriceDiscriminationPricePanel(a)showsamonopolythatchargesthesamepricetoallcustomers.Totalsurplusinthismarketequalsthesumofprofit(producersurplus)andconsumersurplus.Panel(b)showsamonopolythatcanperfectlypricediscriminate.Becauseconsumersurplusequalszero,totalsurplusnowequalsthefirm’sprofit.Comparingthesetwopanels,youcanseethatperfectpricediscriminationraisesprofit,raisestotalsurplus,andlowersconsumersurplus.Quantity0(a)MonopolistwithSinglePricePriceQuantity0(b)MonopolistwithPerfectPriceDiscriminationProfitConsumersurplusDeadweightlossMonopolypriceQuantitysoldMarginalrevenueDemandMarginalcostQuantitysoldProfitDemandMarginalcostPriceDiscriminationExamplesofpricediscriminationMovieticketsLowerpriceforchildrenandseniorsAirlinepricesLowerpriceforround-tripwithSaturdaynightstay?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.32“WoulditbotheryoutohearhowlittleIpaidforthisflight?”PriceDiscriminationExamplesofpricediscriminationDiscountcouponsNotallcustomersarewillingtospendtimetoclipcouponsFinancialaidHightuitionandneed-basedfinancialaidWillingnesstopayQuantitydiscountsCustomerpaysahigherpriceforthefirstunitboughtthanforthelastunitbought?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.33PublicPolicyTowardMonopoliesIncreasingcompetitionwithantitrustlawsShermanAntitrustAct,1890ClaytonAntitrustAct,1914PreventmergersBreakupcompaniesPreventcompaniesfromcoordinatingtheiractivitiestomakemarketslesscompetitive?2015CengageLearning.AllRightsReserved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-