英文版产业经济学教程第4章价格歧视.ppt

Chapter4Pricediscrimination ECNUOrientalRealEstateCollege 4 1Definition Aprevalentmarketingskillandeconomicphenomena preferentialpriceorquantitydiscount eg Sometimespeoplewillthinkthatiffirmschargedifferentpriceondifferentconsumersforthesamegoods itmeanspricediscrimination Butthisunderstandingisincomplete Inmuchcase discretepricemaybeonlyreflecttrafficcostandsalescostfee Andincertaincase universalpricemeansdiscriminationonthecontrary fixedfeeinbuseg Pricediscriminationmeansonefirmsalestheidenticalgoodstodifferentconsumerswithdifferentnetprice Philips 1983 Netprice subtractproductdifferencefromgoodsprice Ifpricedifferentiationjustreflectsthecostdifferenceofsupplyingtodifferentconsumers wedeempricediscriminationdoesn texist Ratiotest Harrypotter inpainlypackededitionvs deluxeedition eg Atthesametime wecan tsayprovidingdifferentqualitygoodstodifferentconsumersmeansnodiscrimination Reasonofprovidingserviceindifferentquality suchasclassedcabininaircraftsandtrains partlyistogetconsumerssurplusbysegmentingconsumersintodifferentgroupsTheconceptof identical goods BMWinUSAisthesametoinGerman Generalequilibriumtheoristmaypointoutwithsomeexcuse goodsdeliveredindifferenttime differentlocationanddifferentstateordifferentqualityisdifferentgoods soscopeofpurepricediscriminationisverylimited Conditionsofpricediscrimination 1 firmsmusthasmarketpower Weoftenconfineitinmonopolyoroligopolymarket onlywhenfirmscanpricehigherthanmarginalcost cantheychargedifferentpriceondifferentconsumers LocayandRodriguez 1992 competitivefirmsispossibletopracticepricediscrimination ifconsumerspurchaseingroupunit 2 theabilityofeffectivemarketsegmentation 3 ensureofnoarbitrage Marketsegmentation Canwefindarightwaytoconductmarketsegmentation theresultmustberelatedtopriceelasticityandWTP willingtopay statusgenderageLocationtimeusePurchasingamount Kindsofarbitrages Possibilityofpricediscriminationisrelatedwithpossibilityofarbitrage Onekindofarbitrageisrelatedwithtransferabilityofgoods Iftransactioncostislow pricediscriminationwillencounterarbitrage namelylow priceconsumerswillbuyforresellingtohigh priceconsumers Transactioncostprovidesonecluetofeasibilityofpricediscrimination Absolutearbitrageornoarbitrageisonlytwoextremecase Generally somelimitedarbitragewilloccurs itdependsonrelativecostandincome Theotherkindofarbitrageisrelatedwithtransferabilityofdifferentconsumepackagesorbundlesprovidedtoconsumers Thatnotmeansphysicaltransferofgoodsamongconsumers Thatmeansfirmstrytomakeeverybuyerreallyselectconsumepackagedesignedforhim notforothers Incentivecompatibilityandself selection Influenceofarbitrage Influenceoftwokindsofarbitrageisdifferent Transferabilityofgoodsisinclinedtopreventdiscrimination Transferabilityofdemandmaycausefirmsincreasediscrimination Threekindsofpricediscrimination Perfectpricediscrimination suppliersgetallconsumersurplusinconditionofholdingperfectinformationofwillingpayment Second degreepricediscrimination suppliersextractconsumersurplusincompletelyusingself selectionwheninformationofindividualpreferenceisincomplete Third degreepricediscrimination Marketsegmentationusingdirectinformationaboutdemandsuchasage professionandlocationetc andsetdifferentpriceforeachgroup 4 2Perfectpricediscrimination simplestcase singleconsumer orsomeidenticalconsumers hasoneunitofdemand Monopolymakepriceequaltoreserveprice gettingallconsumersurplus Aclassicalexample adoctorisalittlevillagesimilarwitheverybodyinthereandtheireconomicinformation Heestimateshowmucheveryoneiswillingtopayforandthenchargeforthatamount Anothercase airlinecompanypayforeachaircraftindifferentprice 2 Complexcase assumption nconsumersholdthesamedemandcurve andmonopolyknowaboutit q D p n soD p nqTgrossofconsumers paymentTwopricingprojects linearpricingandtwoparttariffLinearpricing T pqTwoparttariff T A pq Profitmaximization Inlinearpricing monopolyprice p Twoparttariff setasnetconsumersurplusincompetitivepricep set licensefee A sopricingprojectasbelowT q Profitcompare Monopolypricing Twoparttariff 0 Ifq 0 Ifq 0 Profitcompare D MC A B C ABC Obviously alltheconsumersurplusisgrabbedintwoparttariff 3 Universalcase Assumption consumersholddifferentdemandcurves andmonopolyknowaboutthem Optimalproject setp andaskeachconsumerpayitsnetsurplusas licensefee namelyProblemofinformationrevealwhenconsumerhasunitdemandandsupplieronlyknowdistributionofestimationamongthembutnoabouteveryone sestimation itwillsetsingleprice meansnopricediscrimination HowtomakePerfectpricediscrimination Infactit saquestionofinformationemergingCompretivelyusecouponoraccumulatedconsumingvolumesAuctionorbidPricinginbindBargainingdirectly 优惠券的使用 JournalofMarketingResearch 1978 表中条目是有使用优惠券倾向的全职主妇购买商品的比例括号中的数字表示所表示比例的抽取样本中人数 4 3Third degreepricediscrimination Multi market assumption Monopolycansegmentconsumersinsomegroupsaccordingtosomeexogenousinformation andknowabouteachoftheirdemandcurves Noarbitrageamonggroups andmonopolycan tpractisepricediscriminationinonegroup Aspecialexampleofmultipleproductsmonopolypricing independentdemandandinterdependentcost Howtopreventarbitrage 持卡 凭证担保 转售限制 尤其是对于中间商 掺杂交易费用合约垂直一体化专栏 航空公司如何防止套利 Profitmaximization GeneraldemandProfitfunctionAccordingtoInverseelasticityrule Lernerindex ineverymarketshouldexistsOptimalpricingmeanssettingcomparativelyhighpriceinmarketwithlowerelasticity MR1 D1 MR2 D2 MC p1 p2 Q1 Q2 Welfarecompare CompareitwiththeresultofuniformpricingAssumethatscalerewardfixed Cisconstant Profitandsurplus Incaseofpricediscrimination priceinmarketiispi profitasbelowGeneralconsumersurplusisIncaseofuniformpricing priceis salesamountinmarketIis profitasbelowGeneralconsumersurplusis Differenceonwelfare GeneraldifferenceequalstochangeofsurplusplusprofitTosetuplimitanddownlimit makeFunctionofNSWisconvexfunctionofmarketprice andS p D p accordingtoLagrangemediantheory wecangetSo ifpricediscriminationcannotincreasesalesvolume welfarewillbereduced Thatisthenecessaryconditionofexistenceofpricediscriminationinthesocialangle Conclusion Generally thewelfareeffectofthethird degreepricediscriminationisuncertain Itdependsonthecomparebetweenlossoflow elasticitycomparisonandgainofhigh elasticityconsumersandsuppliers Oneofthecentralquestioninpolicyisitsinfluencetoincomedistribution Pricediscriminationtransfersbenefitoflow elasticityconsumerspartlytohigh elasticityconsumersandsuppliers Itmaybenotappropriate butasweknow low elasticityconsumersaregenerally notalways richergroup 三级价格歧视实例1 三级价格歧视实例2 迪斯尼世界门票价格 2006 4 4Second degreepricediscrimination Assumption consumerdemandisheterogeneous Ifmonopolyknowabouttastesofallconsumers itcanmakeperfectpricediscriminationthroughprovidingpersonalconsumepackagesorbundles Butmonopolygenerallycannotclassifyconsumersaccordingtosomeexplicitinformation anditcanprovideamenuforselection Thenpossibilityofarbitragemustbeconsidered namelyconsumersbelongingtoonegroupmaychooseconsumepackagedesignedforothergroups Therestrictionofself selectionorincentive compatible 4 4 1indirectpricediscriminationbasedontime 航空公司基于订票时间的价格歧视 p 起飞时间 预售时间 票价与提前订票时间的关系 提前订票时间 2 3天 4 4 2Indirectpricediscriminationbasedonquality ProductlineswithdifferentqualitystatusDifferentkindsofconsumers highvaluetype lowvaluetypeCommonstrategy harmed goods IBM Sony Intel p Productstatus 400 350 300 600 486SX 486 质量歧视的三个决策 厂商应该确定几种不同的等级 实践表明 三个而不是两个等级是最优的 各个等级水平如何选择 如何为每个等级的产品制定相应的价格 参与约束 激励相容约束 例 参考价格对高价位产品的影响 4 4 3Indirectpricediscriminationbasedonquantity quantitydiscount taxifeeelectricpowerusePackagestrategy quantity priceportfolio 英国移动通信公司的二部定价套餐 此外还有 移动的动感地带短信套餐等 4 5Comparisionamongseveralmethodsinnonlinearpricing Two parttariff T q A pq providesamenuofconsumebundlesinaline Generallythelinedoesnotpassorigin Simplicityisitsprimaryattraction andsometimesitdependsonpossibilityoflimitedarbitrage Fullarbitrageisprevented namelyonlyonebuyerpaysforfixedfeeA andthenresalegoodstootherconsumers Notice actuallytwo parttariffcorrespondstoquantitydiscount averagepricedecreasewithincreaseofconsumequantity Profitandwelfare Assumption consumersreferenceasbelowU V 0 0 V q 0 V q 0 isaconstantoftaste differentinperson V isuniformtoeveryone Alsothesecanbeexplainedinthesamepreferenceofconsumersbutwithdifferentincomelevel Compareamongcaseofperfectdiscrimination monopolypricingandtwo parttariff V q TiftheypayTandconsumeq 0iftheydonotbuy Asimplemodel Twokindsofconsumers proportionoftasteparameterbeing 1is proportionoftasteparameterbeing 2is1 Assumethat 2 1 monopolyproduceinfixedcostc andc 1 2 forsimplicity assumesoV q 1 q Utilityfunction Notice fixedcostonlyinfluencethedecisionofbuyingornot Onceconsumersdecidetobuy itisoutofconsider Consumerutilitymaximization U iV q pqFirst ordercondition iV q pAccordingtoassumptionbefore i 1 q pSo demandfunctioniseducedasq Di p 1 p iNetconsumersurplusis Generaldemandfunction Inthiscase consumersurplusisNoticethat and 2typeconsumersalwaysholdhighersurplus Make asharmonicmeanof 1and 2Thengeneraldemandinpricepis 2 1 p P1 c D1 D2 S2 p S1 p Case1 perfectpricediscrimination Assumethatmonopolycanobserve idirectly Thenitcansetmarginalpriceasp1 c andsetpersonalfixedfeeManufacturer smonopolisticprofitisLeavedistributionquestionoutofaccount welfarehereisoptimal Case2 Monopolypricing Assumethatconsumershavecompletearbitrage sothatmonopolycanonlysetuniformprice T q pqProfitis p c D p andD p 1 p MonopolypriceisMonopolisticprofitisHereweassumethatmonopolydecidestoprovidegoodstotwokindsofconsumers Itneed c 2 2 1 or islargeenough Case3 Two parttariff Assumealsothatmonopolyprovidesgoodstotwokindsofconsumers Setmarginalpricep Maximalfixedfeethatcanmake 1typeconsumersbuygoodsisA S1 p Then 2typeconsumerswillpurchase becauseSoprofitfunctionofmonopolyisPriceofprofitmaximizationisSimply wecanseethatprofitoftwo parttariffisasgoodasinlinearpricingatleast thelatecanbeseenasthespecialcaseoftheformer Comparisoninwelfareeffect It ssimpletojudgethatAndalso inthecaseofsupplyingtwokindsofconsumersatthesametime marginaloftwo parttariffisbetweencompetitivepriceandmonopolyprice namelyNotice welfareundertwo parttariffishigherthaninlinearpricing becausemarginalpricedecreasingwillbringpurchasingmorebytwokindsofconsumers sodistortionisreduced Tomonopoly itcanmakeuplossbyfixedfeewhendecreasingprice Sofixedfeewillinducemonopolydecreasepricesothatwelfareisgained Conclusion Wecanmakeamorecomplexprojecttogetmoreprofitthroughcompletenonlinearpricing processomitted Conclusion1 low demandconsumersdonotgetnetsurplus whilehigh demandconsumerscangetpositivenetsurplus Conclusion2 effectiverestrictiontopersonalarbitragewillpreventhigh demandconsumersbuylow demandbundles Conclusion3 high demandconsumersbuysociallyoptimalquantity andlow demandconsumersbuyquantitylowerthanoptimalquantity 4 6Qualitydiscrimination Monopolycanalsopractisediscriminationthroughprovidingdifferentqualitygoodstodifferenttastyconsumers Itisverysimilartoquantitydiscrimination Assumethatconsumershaveunitd