Ch07_Pindyck生产成本

Chapter7成本©2005PearsonEducation,Inc.Chapter72TopicstobeDiscussed衡量成本?短期成本长期成本长期和短期成本曲线©2005PearsonEducation,Inc.Chapter73TopicstobeDiscussedProductionwithTwoOutputs:EconomiesofScope规模经济DynamicChangesinCosts:TheLearningCurve长期成本曲线©2005PearsonEducation,Inc.Chapter745.1衡量成本Forafirmtominimizecosts,wemustclarifywhatismeantbycostsandhowtomeasurethemItisclearthatifafirmhastorentequipmentorbuildings,therenttheypayisacostWhatifafirmownsitsownequipmentorbuilding?Howarecostscalculatedhere?©2005PearsonEducation,Inc.Chapter75MeasuringCost:WhichCostsMatter?AccountingCost会计成本实际发生的费用和固定资产的折旧EconomicCost经济成本企业在生产中所使用的资源的成本©2005PearsonEducation,Inc.Chapter76MeasuringCost:WhichCostsMatter?Opportunitycost机会成本企业未将资源用于其他可供选择的最佳用途而放弃的机会相联系的成本©2005PearsonEducation,Inc.Chapter77MeasuringCost:WhichCostsMatter?Althoughopportunitycostsarehiddenandshouldbetakenintoaccount,sunkcostsshouldnotSunkCost沉没成本已经发生但无法收回的支出在制定未来经济决策时应当忽略它。©2005PearsonEducation,Inc.Chapter78SunkCostFirmbuysapieceofequipmentthatcannotbeconvertedtoanotheruse专用设备ExpenditureontheequipmentisasunkcostHasnoalternativeusesocostcannotberecovered–opportunitycostiszeroDecisiontobuytheequipmentmighthavebeengoodorbad,butnowdoesnotmatter©2005PearsonEducation,Inc.Chapter79ProspectiveSunkCostAnExampleFirmisconsideringmovingitsheadquartersAfirmpaid$500,000foranoptiontobuyabuildingThecostofthebuildingis$5millionforatotalof$5.5millionThefirmfindsanotherbuildingfor$5.25millionWhichbuildingshouldthefirmbuy?©2005PearsonEducation,Inc.Chapter710ProspectiveSunkCostExample(cont.)ThefirstbuildingshouldbepurchasedThe$500,000isasunkcostandshouldnotbeconsideredinthedecisiontobuyWhatshouldbeconsideredisSpendinganadditional$5,250,000orSpendinganadditional$5,000,000©2005PearsonEducation,Inc.Chapter711MeasuringCost:WhichCostsMatter?总成本包括:1.FixedCost固定成本Doesnotvarywiththelevelofoutput2.VariableCost可变成本CostthatvariesasoutputvariesVCFCTC©2005PearsonEducation,Inc.Chapter712FixedandVariableCosts什么成本是固定的，什么是可变的，和时间长短有关在短期内大多数成本固定长期内大多数成本可变©2005PearsonEducation,Inc.Chapter713固定成本与沉没成本他们经常被混淆FixedCost在企业经营中必须支付的成本，与产出水平无关影响企业决策SunkCost已经发生无法收回的成本。不影响决策将沉淀成本按摊销方式处理。不区分沉淀成本和固定成本©2005PearsonEducation,Inc.Chapter714边际成本MarginalCost(MC):ThecostofexpandingoutputbyoneunitFixedcostshavenoimpactonmarginalcost,soitcanbewrittenas:ΔqΔTCΔqΔVCMC©2005PearsonEducation,Inc.Chapter715平均成本AverageTotalCost(ATC)CostperunitofoutputAlsoequalsaveragefixedcost(AFC)plusaveragevariablecost(AVC)qTVCqTFCqTCATCAVCAFCqTCATC©2005PearsonEducation,Inc.Chapter7167.2短期成本©2005PearsonEducation,Inc.Chapter717短期成本的决定因素–Anxample考察生产与成本的关系假设工资固定VC=wLqLwqVCMC©2005PearsonEducation,Inc.Chapter718DeterminantsofShortRunCosts–AnExample因为LMPLQLL1Lfora1unitQQMP获得额外一单位产出所需要的额外的劳动数量为©2005PearsonEducation,Inc.Chapter719DeterminantsofShortRunCosts–AnExample所以LMPMCw较低的劳动边际产量(MPL)味着较高的边际成本(MC)。每当劳动的边际产量降低时，边际成本上升短期内，边际成本等于变化的投入要素的价格除以其边际产量©2005PearsonEducation,Inc.Chapter720边际报酬递减和边际成本边际报酬递减——边际产量下降——边际成本上升©2005PearsonEducation,Inc.Chapter721成本曲线OutputCost($peryear)100200300400012345678910111213VCVariablecostincreaseswithproductionandtheratevarieswithincreasinganddecreasingreturns.TCTotalcostistheverticalsumofFCandVC.FC50Fixedcostdoesnotvarywithoutput©2005PearsonEducation,Inc.Chapter722CostCurves020406080100120024681012Output(units/yr)Cost($/unit)MCATCAVCAFC©2005PearsonEducation,Inc.Chapter723CostCurvesWhenMCisbelowAVC,AVCisfallingWhenMCisaboveAVC,AVCisrisingWhenMCisbelowATC,ATCisfallingWhenMCisaboveATC,ATCisrisingTherefore,MCcrossesAVCandATCattheminimumsTheAverage–Marginalrelationship©2005PearsonEducation,Inc.Chapter724CostCurvesforaFirmThelinedrawnfromtheorigintothevariablecostcurve:ItsslopeequalsAVCTheslopeofapointonVCorTCequalsMCTherefore,MC=AVCat7unitsofoutput(pointA)12345678910111213OutputP100200300400FCVCTCA©2005PearsonEducation,Inc.Chapter7257.3长期成本长期内厂商能改变所有投入要素，因而改变规模为了实现成本最小化，厂商需要选择合适的投入要素组合©2005PearsonEducation,Inc.Chapter726CostintheLongRun租入资本=自有资本AssumeDeltaisconsideringpurchasinganairplanefor$150millionPlanelastsfor30years$5millionperyear–economicdepreciationfortheplane©2005PearsonEducation,Inc.Chapter727CostintheLongRun如果场上没有购买飞机则可以将资本存银行获得利息收入$150million这是机会成本使用者成本=机会成本+经济折旧=利率*资产价值+经济折旧©2005PearsonEducation,Inc.Chapter728CostintheLongRunUserCostofCapital=EconomicDepreciation+(InterestRate)*(ValueofCapital)=$5mil+(.10)($150mil–depreciation)Year1=$5million+(.10)($150million)=$20millionYear10=$5million+(.10)($100million)=$15million©2005PearsonEducation,Inc.Chapter729CostintheLongRun每单位资本的使用者成本：r=折旧率+利率Inourexample,depreciationratewas3.33%andinterestwas10%,sor=3.33%+10%=13.33%©2005PearsonEducation,Inc.Chapter730成本最小化的投入选择假设：两个可变投入:Labor(L)andcapital(K)劳动的价格：工资(w)资本的价格：r=折旧率+利率（使用者成本）Or资本价格：=租金率r©2005PearsonEducation,Inc.Chapter731CostintheLongRun等成本线C=wL+rK©2005PearsonEducation,Inc.Chapter732CostintheLongRunRewritingCasanequationforastraightline:K=C/r-(w/r)L等成本线的斜率=-(w/r)rwLK©2005PearsonEducation,Inc.Chapter733给定产量的成