andCostAnalysisPartIIMGrowHill微观经济学讲义课件

LaugherCurve Economistshaveforecastednineoutofthelast15recessions.MakingLong-RunProductionDecisionsTomaketheirlong-rundecisions,firmslookatcostsofvariousinputsandthetechnologiesavailableforcombiningtheseinputs,andthendecidewhichcombinationoffersthelowestcost.MakingLong-RunProductionDecisionsThefirmmakeslong-rundecisionsonthebasisoftheexpectedcosts,andexpectedusefulness,ofinputs.TechnicalEfficiencyandEconomicEfficiencyTechnicalefficiencyisasituationinwhichasfewinputsaspossibleareusedtoproduceagivenoutput.Technicalefficiencyisefficiencythatdoesnotconsidercostofinputs.TechnicalEfficiencyandEconomicEfficiencyTheeconomicallyefficientmethodofproductionisthatmethodthatproducesagivenlevelofoutputatthelowestpossiblecost.Itistheleast-costtechnicallyefficientprocess.DeterminantsoftheShapeoftheLong-RunCostCurveThelawofdiminishingmarginalproductivitydoesnotholdinthelongrunsinceallinputsarevariableinthelongrun.DeterminantsoftheShapeoftheLong-RunCostCurveTheshapeofthelong-runcostcurveisduetotheexistenceofeconomiesanddiseconomiesofscale.ATypicalLong-RunAverageTotalCostTableQuantityTotalCostsofLaborTotalCostofMachinesTotalCosts=TCL+TCMAverageTotalCosts=TC/Q11121314151617181920$381390402420450480510549600666$254260268280300320340366400444$6356506707007508008509151,0001,110$58545250505050515356AveragetotalcostCostsperunit$64626058565452504811121314151617181920QuantityMinimumefficientlevelofproductionATypicalLong-RunAverageTotalCostCurveEconomiesofScaleThereareeconomiesofscaleinproductionwhentheper-unitoutputcostdecreasesasoutputincreaseswhenallinputsarechangeable.Inreal-worldproductionprocesses,economiesofscaleareextremelyimportantatlowlevelsofproduction.EconomiesofScaleAnindivisiblesetupcost

isthecostofanindivisibleinputforwhichacertainminimumamountofproductionmustbeundertakenbeforetheinputbecomeseconomicallyfeasibletouse.EconomiesofScaleIndivisiblesetupcostscreatemanyreal-worldeconomiesofscale.Thecostofablastfurnaceoranoilrefineryisanexampleofanindivisiblesetupcost.EconomiesofScaleBecauseoftheimportanceofeconomiesofscale,businesspeopleoftentalkofaminimumefficientlevelofproduction.EconomiesofScaleTheminimumefficientlevelofproductionistheamountofproductionthatspreadssetupcostsoutsufficientlyforfirmstoundertakeproductionprofitably.EconomiesofScaleTheminimumefficientlevelofproductionwillbeatthebeginningoftheconstantreturnsportionoftheaveragecostcurve—whereaveragetotalcostsareataminimum.EconomiesofScaleTheminimumefficientlevelofproductionisreachedoncethesizeofthemarketexpandstoasizelargeenoughsothatfirmscantakeadvantageofalleconomiesofscale.DiseconomiesofScaleDiminishingmarginalproductivityreferstothedeclineinproductivitycausedbyincreasingunitsofavariableinputbeingaddedtoafixedinput.DiseconomiesofScaleDiseconomiesofscalerefertodecreasesinproductivitywhichoccurwhenthereareequalincreasesofallinputs(noinputisfixed).Diseconomiesofscaleoccurontherightsideofthegraphofthelong-runaveragecostcurvewhereitisupwardsloping,meaningthataveragecostisincreasing.DiseconomiesofScaleAsthesizeofthefirmincreases,monitoringcostsgenerallyincrease.Monitoringcostsarethoseincurredbytheorganizerofproductioninseeingtoitthattheemployeesdowhattheyaresupposedtodo.Asthesizeofthefirmincreases,teamspiritormoralegenerallydecreases.Teamspiritisthefeelingsoffriendshipandbeingpartofateamthatbringsoutpeoples’besteffortDiseconomiesofScaleLossofteamspiritcancontributetodiseconomiesofscale.ConstantReturnstoScaleConstantreturnstoscaleiswherelong-runaveragetotalcostsdonotchangeasoutputincreases.ItisshownbytheflatportionoftheLRATCcurve.AveragetotalcostCostsperunit$64626058565452504811121314151617181920QuantityEconomiesandDiseconomiesofScaleEconomiesofScaleDiseconomiesofScaleConstantreturnstoScaleImportanceofEconomiesandDiseconomiesofScaleEconomiesanddiseconomiesofscaleplayimportantrolesinreal-worldlong-runproductiondecisions.ImportanceofEconomiesandDiseconomiesofScaleThelong-runandtheshort-runaveragecostcurveshavethesameU-shape,buttheunderlyingcausesoftheseshapesdiffer.ImportanceofEconomiesandDiseconomiesofScaleEconomiesanddiseconomiesofscaleaccountfortheshapeofthelong-runtotalcostcurve.ImportanceofEconomiesandDiseconomiesofScaleTheassumptionofinitiallyincreasingandtheneventuallydiminishingmarginalproductivity(asavariableinputisaddedtoafixedinput)accountsfortheshapeoftheshort-runcostcurve.TheEnvelopeRelationshipInthelongrunallinputsareflexible,whileintheshortrunsomeinputsarenotflexible.Asaresult,long-runcostwillalwaysbelessthanorequaltoshort-runcost.TheEnvelopeRelationshipIntheshortrunthefirmfacesanadditionalconstraint:allexpansionmustproceedusingonlythevariableinput.Theseadditionalconstraintsincreasecost.TheEnvelopeRelationshipTheenveloperelationshipexplainsthat:Attheplannedoutputlevel,short-runaveragetotalcostequalslong-runaveragetotalcost.Atallotherlevelsofoutput,short-runaveragetotalcostishigherthanlong-runaveragetotalcost.Costsperunit0QuantitySRATC2SRATC3SRATC4LRATCSRATC1SRMC1SRMC2SRMC3SRMC4Q2Q3EnvelopeofShort-RunAverageTotalCostCurvesEntrepreneurialActivityandtheSupplyDecisionProfitiswhatunderliesthedynamicsofproductioninamarketeconomy.Theexpectedprofitperunitmustexceedtheopportunitycostofsupplyingthegoodforagoodtobesupplied.EntrepreneurialActivityandtheSupplyDecisionThesupplier’sexpectedeconomicprofitperunitisthedifferencebetweentheexpectedpriceofagoodandtheexpectedaveragetotalcostofproducingit.EntrepreneurialActivityandtheSupplyDecisionCostcurvesdonotbecomesupplycurvesthroughsomemagicprocess.Tomovefromcosttosupply,entrepreneurialinitiativeisrequired.EntrepreneurialActivityandtheSupplyDecisionAnentrepreneur

isanindividualwhoseeanopportunitytosellanitematapricehigherthantheaveragecostofproducingit.EntrepreneurialActivityandtheSupplyDecisionEntrepreneursorganizeproduction.Theyaretheoneswhovisualizesthedemandandconvincestheindividualswhoownthefactorsofproductionthattheywanttoproducethosegoods.EntrepreneurialActivityandtheSupplyDecisionTheentrepreneuralsomustconvincedemandersthatwhattheentrepreneurisproducingiswhatthedemanderswant.EntrepreneurialActivityandtheSupplyDecisionWithoutentrepreneurstherewouldbelittlesupplybecausetherewouldbenoonetorecognizeandactondemandpotential.EntrepreneurialActivityandtheSupplyDecisionByallowingentrepreneurstoearnprofit,marketeconomiesencouragepeopletochanneltheirdriveintosupplyingmaterialgoods.EntrepreneurialActivityandtheSupplyDecisionCostentersintothesedecisionsasacutoffsinceentrepreneurswhodonotcovertheircostsgenerallydonotstayinbusiness.EntrepreneurialActivityandtheSupplyDecisionThegreaterthedifferencebetweenpriceandaveragetotalcost,thegreatertheentrepreneur’sincentivetotackletheorganizationalproblemsandsupplythegood.UsingCostAnalysisintheRealWorldSomeoftheproblemsofusingcostanalysisintherealworldincludethefollowing:EconomiesofscopeLearningbydoingandtechnologicalchangeManydimensionsUnmeasuredcostsEconomiesofScopeThecostofproductionofoneproductoftendependsonwhatotherproductsafirmisproducing.EconomiesofScopeThereareeconomiesofscopewhenthecostsofproducinggoodsareinterdependentsothatitislesscostlyforafirmtoproduceonegoodwhenitisalreadyproducinganother.EconomiesofScopeFirmslookforbotheconomiesofscopeandeconomiesofscale.Economiesofscopeplayanimportantroleinfirms’decisionsofwhatcombinationofgoodstoproduce.EconomiesofScopeGlobalization,byallowingfirmstosegmenttheproductionprocess,hasmadeeconomiesofscopeevenmoreimportanttofirmsintheirproductiondecisions.LearningbyDoingandTechnologicalChangeProductiontechniquesavailabletoreal-worldfirmsareconstantlychangingbecauseoflearningbydoingandtechnologicalchange.Thesechangesoccurovertimeandcannotbeaccuratelypredicted.LearningbyDoingandTechnologicalChangeLearningbydoingmeansthataswedosomething,welearnwhatworksanddoesn’t,andovertimewebecomemoreproficientatit.LearningbyDoingandTechnologicalChangeTheconceptoflearningbydoingemphasizestheimportanceofthepastintryingtopredictperformance.Theexperiencedfailedmanagerispreferabletotherookie.LearningbyDoingandTechnologicalChangeManyfirmsestimateworkerproductivitytogrow1to2percentayearbecauseoflearningbydoing.LearningbyDoingandTechnologicalChangeTechnologicalchangeisanincreaseintherangeofproductiontechniquesthatprovidesnewwaystoproducinggoods.LearningbyDoingandTechnologicalChangeTechnologicalchangeoffersanincreaseintheknownrangeofproduction.LearningbyDoingandTechnologicalChangeWheneverlearningbydoingortechnologicalchangeoccurs,thecostcurveshiftsdownsincethesameoutputcanbeproducedatalowercost.LearningbyDoingandTechnologicalChangeInsomeindustriessuchasthecomputerbusiness,technologicalchangeisoccurringsofastthatitoverwhelmsallothercostissues.Technologicalchangeoccursinlow-techbusinessesaswell.LearningbyDoingandTechnologicalChangeMoore'slawstatesthatthecostofcomputingwillfallbyhalfevery18months.Asthepriceofcomputerchipsfalls,otherindustriesareaffectedaswell.LearningbyDoingandTechnologicalChangeInmanybusinesses,theeffectoflearningbydoingandtechnologicalchangeonpricesisbuiltintothefirm'spricingstructure.Firmsmaypricelowintheexpectationoflowercostsduetolearningbydoingandtechnologicalchange.ManyDimensionsMostdecisionsthatfirmsmakeinvolvemorethanonedimension.Theonlydimensioninthestandardmodelisthelevelofoutput.Goodeconomicdecisionstakeallrelevantmarginalcostsandbenefitsintoaccount.ManyDimensionsTheimportantthingtorememberinusingthestandardmodelisthereasoning,notthe