经济学（微观）（英文版原书第7版）课件 第2章　权衡、比较优势和市场制度

EconomicsSeventhEditionChapter2Trade-offs,ComparativeAdvantage,andtheMarketSystemCopyright©2019,2017,2015PearsonEducation,Inc.AllRightsReserved.ChapterOutline2.1

ProductionPossibilitiesFrontiersandOpportunityCosts2.2

ComparativeAdvantageandTrade2.3

TheMarketSystemScarcityandTrade-offsHouseholds,firmsandgovernmentscontinuallyfacedecisionsabouthowbesttousetheirscarceresources.Scarcity:asituationinwhichunlimitedwantsexceedthelimitedresourcesavailabletofulfillthosewants.Scarcityrequirestrade-offs.Economicsteachesustoolstohelpmakegoodtrade-offs.Example:Whendecidinghowtouseitsscarceworkersandmachinery,ifTeslawantstoproducemoreModel3s,thoseresourceswillnotbeavailabletoproduceModelSs.2.1ProductionPossibilitiesFrontiersandOpportunityCostsUseaproductionpossibilitiesfrontiertoanalyzeopportunitycostsandtrade-offs.Aproductionpossibilitiesfrontier(PPF)isacurveshowingthemaximumattainablecombinationsoftwogoodsthatcanbeproducedwithavailableresourcesandcurrenttechnology.IsthePPFapositiveornormativetool?Positive;itshows“whatis”,not“whatshouldbe”.Figure2.1Tesla’sProductionPossibilitiesFrontier(1of2)Teslacanproduceitsoriginalmodels,oritsnewModel3s.ProducingmoreModel3srequiresreducingthenumberoforiginalmodelsproduced.PointsonthePPFareattainableforTesla.Pointsbelowthecurveareinefficient.Pointsabovethecurveareunattainablewithcurrentresources.Figure2.1Tesla’sProductionPossibilitiesFrontier(2of2)Toproduce20moreModel3s(e.g.movingfromAtoB),Teslamustproduce20feweroriginalmodels.The20feweroriginalmodelsistheopportunitycostofproducing20moreModel3s.Opportunitycost:Thehighest-valuedalternativethatmustbegivenuptoengageinanactivity.Figure2.2IncreasingMarginalOpportunityCostsOnthepreviousslide,opportunitycostswereconstant.Butopportunitycostsareoftenincreasing.Why?Someresourcesarebettersuitedtoonetaskthananother.Thefirstresourcesto“switch”aretheonebestsuitedtoswitching.Themoreresourcesalreadydevotedtoanactivity,thesmallerthepayofftodevotingadditionalresourcestothatactivity.Figure2.3EconomicGrowth(panel(a))Asmoreeconomicresourcesbecomeavailable,theeconomycanmovefrompointAtopointB,producingmoretanksandmoreautomobiles.Shiftsintheproductionpossibilitiesfrontierrepresenteconomicgrowth.Economicgrowth:theabilityoftheeconomytoincreasetheproductionofgoodsandservices.Figure2.3EconomicGrowth(panel(b))Thispanelshowstechnologicalimprovementintheautomobileindustry.Thequantityoftanksthatcanbeproducedremainsunchanged.Asinthepreviousslide,manypreviouslyunattainablecombinationsarenowattainable.ApplytheConcept:APPFforExamGradesSupposeyouhavealimitedamountoftimetostudyfortwoexams,EconomicsandAccounting.Whatwouldtheproductionpossibilitiescurvefortheexamgradeslooklike?Astraightline,likethePPFforTesla’svehicles,orAbowed-outwardcurve,likethePPFfortanksandautomobiles?Answer:2,thefirsthourspentstudyingeconomicsismuchmorevaluable(andhasaloweropportunitycost)thanthelasthour.2.2ComparativeAdvantageandTradeDescribecomparativeadvantageandexplainhowitservesasthebasisfortrade.Youandyourneighboreachhavealimitedtimetopickapplesand/orcherries.Thetableshowstheamountofeachfruitthatyoucouldeachpick,bydevotingallofyourtimetothatfruit.BlankYouBlankYourNeighborBlankBlankApplesCherriesApplesCherriesDevotealltimetopickingapples20pounds0pounds30pounds0poundsDevotealltimetopickingcherries0pounds20pounds0pounds60poundsFigure2.4ProductionPossibilitiesforYouandYourNeighbor,withoutTradeIfyouspendallofyourtimepickingcherries,youcanpick20poundsofcherries;orifyouspendallyourtimepickingapples,youcanpick20poundsofapples.Yourneighborcansimilarlypick60poundsofcherriesor30poundsofapples.SpecializationandTradeWhatifyouandyourneighbordecidedtospecializeandtrade?Trade:Theactofbuyingandselling.Couldyourneighborbenefitfromtrade?Sheisbetteratpickingbothapplesandcherries…Bothofyoucanbenefitfromtrade,byspecializinginwhatyouarerelativelygoodat.Let’sseehow…Figure2.5GainsfromTrade(1of3)Whenyoudon’ttradewithyourneighbor,let’ssayyoupickandconsume8poundsofapplesand12poundsofcherriesperweek—pointAinpanel(a).Whenyourneighbordoesn’ttradewithyou,shepicksandconsumes9poundsofapplesand42poundsofcherriesperweek—pointCinpanel(b).Figure2.5GainsfromTrade(2of3)Ifyouspecializeinpickingapples,youcanpick20pounds.Ifyourneighborspecializesinpickingcherries,shecanpick60pounds.Ifyoutrade10poundsofyourapplesfor15poundsofyourneighbor’scherries,youwillbeabletoconsume10poundsofapplesand15poundsofcherries—pointBinpanel(a).Figure2.5GainsfromTrade(3of3)Yourneighborcannowconsume10poundsofapplesand45poundsofcherries—pointDinpanel(b).Youandyourneighborarebothbetteroffasaresultoftrade.Notethatyourneighborbenefitsfromtradeeventhoughshecouldproducemoreofeitherfruitthanyoucould.Table2.1ASummaryoftheGainsfromTradeBlankYouBlankYourNeighborBlankBlankApples(inpounds)Cherries(inpounds)Apples(inpounds)Cherries(inpounds)Productionandconsumptionwithouttrade812942Productionwithtrade200060Consumptionwithtrade10151045Gainsfromtrade(increasedconsumption)2313Bothyouandyourneighborareabletoconsumemorewithtradethanwithout.ExplainingtheGainsfromSpecializationandTradeHowcouldbothofyoubenefitfromtrade,whenyourneighborwassomuchbetterthanyou?Economistssayyourneighborhadanabsoluteadvantageinbothcherryandapplepicking,butyouhadacomparativeadvantageinpickingapples.Absoluteadvantage:Theabilityofanindividual,afirm,oracountrytoproducemoreofagoodorservicethancompetitors,usingthesameamountofresources.Comparativeadvantage:Theabilityofanindividual,afirm,oracountrytoproduceagoodorserviceataloweropportunitycostthancompetitors.Table2.2OpportunityCostsofPickingApplesandCherriesBlankOpportunityCostofPicking1PoundofApplesOpportunityCostofPicking1PoundofCherriesYou1poundofcherries1poundofapplesYourNeighbor2poundsofcherries0.5poundofapplesThebasisfortradeiscomparativeadvantage,notabsoluteadvantage.Individuals,firms,andcountriesarebetteroffiftheyspecializeinproducinggoodsandservicesforwhichtheyhaveacomparativeadvantageandobtaintheothergoodsandservicestheyneedbytrading.ApplytheConcept:ComparativeAdvantageandHouseworkPeoplelivingtogetherhavetodivideuphouseholdchores.Basiceconomicconceptslikecomparativeadvantagecanprovideusefulinsightinthedivisionoflabor.SupposeJackisfasterthanJillatbothcookingandlaundry.However:JackisMUCHfasteratpreparingtastymeals,whileJackisonlyalittlefasteratdoinglaundryJack’scomparativeadvantageisincooking—tocookatastymeal,hegivesuptheopportunitytoperformlesslaundrythanJill—soheshouldspecializeinthis,whileJillspecializesinlaundry.2.3TheMarketSystemExplainthebasicsofhowamarketsystemworks.Amarketisagroupofbuyersandsellersofagoodorservice,andtheinstitutionorarrangementbywhichtheycometogethertotrade.Twokeygroupsparticipateinthemoderneconomy:Householdsconsistofindividualswhoprovidethefactorsofproduction:labor,capital,naturalresources,andotherinputsusedtomakegoodsandservices.Householdsreceivepaymentsforthesefactorsbysellingthemtofirmsinfactormarkets.Firmssupplygoodsandservicestoproductmarkets;householdsbuytheseproductsfromthefirms.TheFourFactorsofProductionLabor:alltypesofwork,fromthepart-timelaborofteenagersworkingatMcDonald’stotheworkofseniormanagersinlargecorporations.Capital:physicalcapital,suchascomputers,officebuildings,andmachinetools,usedtoproduceothergoods.Naturalresources:land,water,oil,ironore,andotherrawmaterials(or“giftsofnature”)thatareusedinproducinggoods.Anentrepreneurissomeonewhooperatesabusiness.Entrepreneurialabilityistheabilitytobringtogethertheotherfactorsofproductiontosuccessfullyproduceandsellgoodsandservices.Figure2.6TheCircular-FlowDiagram(1of2)Circular-flowdiagram:Amodelthatillustrateshowparticipantsinmarketsarelinked.Householdsprovidefactorsofproductiontofirms.Firmsprovidegoodsandservicestohouseholds.Firmspaymoneytohouseholdsforthefactorsofproduction.Householdspaymoneytofirmsforthegoodsandservices.Figure2.6TheCircular-FlowDiagram(2of2)Likealleconomicmodels,thecircularflowdiagramisasimplifiedversionofreality:NogovernmentNofinancialsystemNoforeignbuyersandsellersofgoodsWewillexplorethesesectorsinlaterchapters.TheGainsfromFreeMarketsAfreemarketisonewithfewgovernmentrestrictionsonhowagoodorservicecanbeproducedorsoldoronhowafactorofproductioncanbeemployed.Countriesthatcomeclosesttothefreemarketbenchmarkhavebeenmoresuccessfulthanthosewithcentrallyplannedeconomiesinprovidingtheirpeoplewithrisinglivingstandards.Thisconceptisnotnew:AdamSmitharguedforfreemarketsinhis1776treatise,AnInquiryintotheNatureandCausesoftheWealthofNations.TheBeautyoftheMarketMechanismItisnotimmediatelyobviousthatmarketswilldobetterthancentrally-plannedsystemsforsatisfyinghumandesires.Afterall,individualsareactingonlyintheirownrationalself-interest.Butmarketswithflexiblepricesallowthecollectiveactionsofhouseholdsandfirmstosignaltherelativeworthofgoodsandservices.Inthisway,the“invisiblehand”allowsindividualresponsestocollectivelyendupsatisfyingthewantsofconsumers.ApplytheConcept:HowDoYouMakeaniPad?HowdoyoumakeaniPad?AlthoughAppleengineersdesignedtheiPad,AppledoesnotmanufactureiPadcomponents,nordoesitassemblethefinalproduct.Hundredsoffirmsareinvolved;manyprobablydon’tevenknowtheirproductswillbeusedinaniPad.Butguidedbytheirownself-interest,theyallcontributetothefinalproduct—withoutanydesiretoenrichAppleorprovideenjoymentforiPadpurchasers.TheRoleoftheEntrepreneurintheMarketSystemAnentrepreneur

issomeonewhooperatesabusiness,bringingtogetherthefactorsofproduction—labor,capital,andnaturalresources—toproducegoodsandservices.Thebestentrepreneurscreateproductsthatconsumersneverevenknewtheywanted.“IfIhadaskedmycustomerswhattheywanted,theywouldhavesaidafasterhorse.”-HenryFordEntrepreneursmakeavitalcontributiontoeconomicgrowth,oftenwithconsiderablepersonalriskandsacrifice.Table2.3ImportantProductsIntroducedbyEntrepreneursatSmallFirmsEntrepreneursmakeavitalcontributiontoeconomicgrowthbyRespondingtoconsumerdemandIntroducingnewproductsGovernmentpoliciesencouragingentrepreneurshiparelikelytoincreaseeconomicgrowthandraisestandardsofliving.ProductInventorAirconditioningWilliamHavilandCarrierAirplaneOrvilleandWilburWrightAutomobile,massproducedHenryFordAutomobilewindshieldwiperMaryAndersonBiomagneticImagingRaymondDamadianBiosyntheticinsulinHerbertBoyerVacuumtube(television)PhiloFarnsworthZipperGideonSundbackTheLegalBasisofaSuccessfulMarketSystemInafreemarket,governmentdoesnotrestricthowfirmsproduceandsellgoods,orhowthey