《国际贸易》芬斯特拉版人大版练习题答案09

ImportTariffsandQuotasunderImperfectCompetition1.Figure9-1showstheHomeno-tradeequilibriumunderperfectcompetition(withthepricePC),andundermonopoly(withthepricePM).Inthisquestion,wecom-parethewelfareofHomeconsumersinthesetwosituations.a.Underperfectcompetition,withthepricePC,labelthetriangleofconsumersurplusandthetriangleofproducersurplus.OutlinetheareaoftotalHomesur-plus(thesumofconsumersurplusandproducersurplus).Answer:RefertoFigure9-1:ConsumersurplusistheareaunderthedemandcurveDandabovethemarketprice,andproducersurplusistheareaabovethemarginalcostcurveMCandbelowthemarketprice.Underperfectcompeti-tion,consumersurplusisPCBPD,wherePDistheintersectionofthedemandcurvewiththeverticalaxis.ProducersurplusisPCBPMC,wherePMCisthein-tersectionofthemarginalcostcurvewiththeverticalaxis.TotalsurplusisthusrepresentedbythetrianglePMCBPD.b.Undermonopoly,withthepricePM,labeltheconsumersurplustriangle.Answer:RefertoFigure9-1:ConsumersurplusisthetrianglePMAPD.c.Producersurplusisthesameastheprofitsearnedbythemonopolist.Tomeasurethis,labelthepointinFigure9-1wheretheMRcurveintersectsMCatpointB.ForsellingtheunitsbetweenzeroandQM,marginalcostsrisealongtheMCcurve,uptoB.ThemonopolistearnsthedifferencebetweenthepricePMandMCforeachunitsold.LabelthedifferencebetweenthepriceandtheMCcurveasproducersurplus,orprofits.Answer:Refertothefollowingfigure:ProducersurplusisrepresentedbythetrapezoidPMABPMC.S-799d.OutlinetheareaoftotalHomesurpluswithaHomemonopoly.Answer:Refertothefigurefrompart(c):TotalsurplusisrepresentedbythetrapezoidPDABPMC.e.Compareyouranswerwithparts(a)and(d)andoutlinethedifferencebetweenthesetwoareas.Whatisthisdifferencecalledandwhy?Answer:Refertothefigurefrompart(c):Thisiscalledthedeadweightlossduetomonopoly,andisrepresentedbythetriangleABB.Itiscalledadeadweightlossbecauseitisalossthatisnotgainedbyanyotherparty.2.Figure9-2showsthefree-tradeequilibriumunderperfectcompetitionandundermonopoly(bothwiththepricePW).Inthisproblem,wecomparethewelfareofHomeconsumersintheno-tradesituationandunderfreetrade.a.Underperfectcompetition,withthepricePW,labelthetriangleofconsumersurplusandthetriangleofproducersurplus.OutlinetheareaoftotalHomesur-plus(thesumofconsumersurplusandproducersurplus).Answer:Refertothefollowingfigure:Thefree-tradeequilibriumunderper-fectcompetitionhasaHomeconsumersurplusofPDBPW,andaproducersur-plusofPWBPMC.S-80Solutions■Chapter9ImportTariffsandQuotasunderImperfectCompetitionPricePDPMPMCPCQCQuantityQMABMCMRDBb.Basedonyouranswertopart(a)inthisproblemandpart(a)ofthelastproblem,outlinetheareaofgainsfromfreetradeunderperfectcompetition.Answer:Refertothefigurefrompart(a):Gainsfromtradearerepresentedbytheshadedtriangle.c.Undermonopoly,stillwiththepricePW,againlabelthetriangleofconsumersurplusandthetriangleofproducersurplus.Answer:Refertothefigurefrompart(a):Thefree-tradeequilibriumundermo-nopolyhasaHomeconsumersurplusofPDBPW,andaproducersurplusofPWBPMC.Thisisidenticaltothefree-tradesurplusunderperfectcompetition.d.Basedonyouranswertopart(c)inthisproblemandpart(d)ofthelastprob-lem,outlinetheareaofgainsfromfreetradeunderHomemonopoly.Answer:Refertothefollowingfigure:Gainsfromtradearerepresentedbytheshadedarea.e.Compareyouranswerwithparts(b)and(d).Thatis,whichareaofgainsfromtradeishigherandwhy?Answer:Thearearepresentinggainsfromtradeislargerinpart(d)thaninpart(b).Thisisbecausetheopeningoftradeinthemonopolycaseeliminatesthemonopolist’sabilitytochargeapricehigherthantheperfectlycompetitiveprice.Solutions■Chapter9ImportTariffsandQuotasunderImperfectCompetitionS-81PriceQuantityGainsfromtradeMCMRBAPDPMPWPMCQMS1D1DBX*=MR*PriceGainsfromtradeMCDX*=MR*MRBABPDPMPWQMS1D1PMCQuantityAssuch,tradeadditionallyeliminatesthedeadweightlossassociatedwithmo-nopoly,makinggainsfromtradehigher.3.RankthefollowinginascendingorderofHomewelfareandjustifyyouranswers.Iftwoitemsareequivalent,indicatethisaccordingly.a.Tarifftinasmallcountrywithperfectcompetition.b.TarifftinasmallcountrywithaHomemonopoly.c.QuotawiththesameimportsMinasmallcountry,withaHomemonopoly.d.TarifftinacountryfacingaForeignmonopoly.Answer:cabd.Asshowninproblem2,asmallcountrywithfreetradehasequivalentlevelsofwelfareundereitherperfectcompetitionormonopoly.Addingatariffineithercasereduceswelfareduetothedeadweightlossassociatedwiththetar-iff,butdoesnotreintroduceanyadditionaldeadweightlossesduetomonopoly.Thus,ab.Aquotainacountrywithamonopolymaintainsthemarketpowerofthemonopolist,andthedeadweightlossduetomonopolyisadditivetothedeadweightlossduetothequota,suchthat:cab.Finally,atariffwithaForeignmonopolycanactuallyincreasewelfareiftheterms-of-tradegainisgreaterthanthedeadweightloss,andifso,abd.4.RefertothepricesofJapaneseautomobileimportsundertheVER(Figures9-5and9-6)andanswer:a.WhatcomponentofthepriceofimportedautomobilesfromJapanrosethemostduringtheperiod1980to1985?Answer:QualityimprovementsincreasedthepriceofJapanesecarsbythemostduringthatperiod.b.SketchhowFigures9-5and9-6mighthavelookediftheU.S.hadappliedatarifftoJapaneseautoimportsinsteadoftheVER(withthesamelevelofim-ports).Inwords,d