曼昆经济学原理第13章

生产本钱Chapter13生产本钱供给定理:当一种物品价格上升时，企业愿意生产并销售更多的这种物品。这种反响导致了向右上方倾斜的供给曲线。企业的目标MaximumProfits企业的经济目标就是要使其获得的利润最大化。企业的总收益与总本钱总收益企业出售其产品所得到的货币量。总本钱企业用于生产的投入品的市场价值。企业的利润利润即企业的总收益减去总本钱 Profit=Totalrevenue-Totalcost作为时机本钱的本钱企业的生产本钱包括所有用来生产商品与效劳的投入品的时机本钱。显性本钱与隐性本钱企业的生产本钱包括显性本钱与隐性本钱。显性本钱〔Explicitcosts〕指企业为购置生产用投入要素而直接支出的货币本钱。隐性本钱〔Implicitcosts〕指不包括在直接货币支出中的投入本钱。经济利润versus会计利润经济学家衡量企业的经济利润用企业的总收益减去生产所销售物品与劳务的总时机本钱〔显性的与隐性的〕。会计师衡量企业的利润用企业的总收益减去显性本钱，也就是说，他们忽略隐性本钱。EconomicProfitversusAccountingProfit当总收益超过显性本钱与隐性本钱，企业将获得经济利润。经济利润小于会计利润。EconomicProfitversusAccountingProfitRevenueTotalopportunitycostsHowanEconomistViewsaFirmExplicitcostsEconomicprofitImplicitcostsExplicitcostsAccountingprofitHowanAccountantViewsaFirmRevenue生产函数与总本钱TheProductionFunction生产函数〔Theproductionfunction〕展示了用于生产一种物品的投入量与该物品的产量之间的关系。边际产量生产过程中任何一种投入的边际产量〔marginalproduct〕是增加一单位投入所引起的产量增加。MarginalProduct投入增量产量增量=边际产量边际产量递减边际产量递减〔Diminishingmarginalproduct〕指一种投入的边际产量随着投入量增加而减少的特征。例如:当越来越多的工人被雇用到企业，每个增加的工人对产量的奉献却越来越少，因为企业的设备数量是有限的。AProductionFunction...QuantityofOutput(cookiesperhour)150140130120110100908070605040302010NumberofWorkersHired012345ProductionfunctionDiminishingMarginalProduct

生产函数的斜率测量了投入品的边际产量，如劳动的边际产量。

随着投入品数量的增加，边际产量不断减少，生产函数变得越来越平坦。从生产函数到总本钱曲线企业生产的产量与本钱的关系决定了价格决策。总本钱曲线展示了产量与本钱的几何关系。AProductionFunctionandTotalCostHungryHelen’sCookieFactoryTotal-CostCurve...TotalCost$8070605040302010QuantityofOutput(cookiesperhour)020401401201008060Total-costcurve本钱的各种衡量指标生产本钱可以被分为固定本钱与可变本钱。固定本钱与可变本钱固定本钱指不随着产量变动而变动的本钱。可变本钱指随着产量变动而变动的本钱。FamilyofTotalCostsTotalFixedCosts(TFC)TotalVariableCosts(TVC)TotalCosts(TC)

TC=TFC+TVCFamilyofTotalCostsQuantityTotalCostFixedCostVariableCost0$3.00$3.00$0.0013.303.000.3023.803.000.8034.503.001.5045.403.002.4056.503.003.5067.803.004.8079.303.006.30811.003.008.00912.903.009.901015.003.0012.00平均本钱平均总本钱〔Averagecosts〕以总本钱除以产量。平均总本钱是每单位产量的本钱。FamilyofAverageCostsAverageFixedCosts(AFC)AverageVariableCosts(AVC)AverageTotalCosts(ATC)ATC=AFC+AVCFamilyofAverageCosts$3.00FamilyofAverageCostsQuantityAFCAVCATC0———1$0.30$3.3021.500.401.9031.000.501.5040.750.601.3550.600.701.3060.500.801.3070.430.901.3380.381.001.3890.331.101.43100.301.201.50边际本钱边际本钱〔Marginalcost(MC)〕指额外一单位产量所引起的总本钱的增加。边际本钱有助于理解如下问题： 生产额外一单位产量的本钱是多少？MarginalCostMarginalCostTotal-CostCurve...$0.00$2.00$4.00$6.00$8.00$10.00$12.00$14.00$16.00024681012QuantityofOutput(glassesoflemonadeperhour)TotalCostTotal-costcurveATCAVCMCAverage-CostandMarginal-CostCurves...$0.00$0.50$1.00$1.50$2.00$2.50$3.00$3.50024681012QuantityofOutput(glassesoflemonadeperhour)

CostsAFC本钱曲线及其形状边际本钱随着产量增加而上升，具有递增的特点。这反映了边际产量递减的性质。CostCurvesandTheirShapes$0.00$0.50$1.00$1.50$2.00$2.50024681012QuantityofOutput(glassesoflemonadeperhour)CostsMCCostCurvesandTheirShapes平均总本钱曲线呈U-形.当产量水平很低时，平均总本钱很高，因为固定本钱分摊到了很少的产量上。当产量增加时，平均总本钱递减。当平均可变本钱上升到能抵销平均固定本钱的递减时，平均总本钱开始上升。CostCurvesandTheirShapesU-形曲线的底端对应着使平均总本钱最小的产量，这种产量有时被称为企业的有效规模。CostCurvesandTheirShapes$0.00$0.50$1.00$1.50$2.00$2.50$3.00$3.50024681012QuantityofOutput(glassesoflemonadeperhour)TotalCostsATC边际本钱与平均总本钱的关系当边际本钱低于平均本钱时，平均本钱下降。当边际本钱大于平均本钱时，平均本钱上升。RelationshipBetweenMarginalCostandAverageTotalCost边际本钱曲线穿过平均总本钱曲线于其有效规模的点上。有效规模即平均总本钱最小的产量。MCATCRelationshipBetweenMarginalCostandAverageTotalCost$0.00$0.50$1.00$1.50$2.00$2.50$3.00$3.50024681012QuantityofOutput(glassesoflemonadeperhour)

Costs各种本钱的计算现在考察各种本钱的计量及其内在的关联。TheVariousMeasuresofCostBigBob’sBagelBinBigBob’sCostCurves...$0.00$2.00$4.00$6.00$8.00$10.00$12.00$14.00$16.00$18.00$20.000246810121416QuantityofOutput(bagelsperhour)TotalCostTotalCostCurveAFCAVCMCBigBob’sCostCurves...00.511.522.533.50246810121416QuantityofOutputCostsATC本钱曲线的三个重要特性当产量增加时，边际本钱最终会上升。平均总本钱曲线是U-形.边际本钱曲线经过平均总本钱曲线的最低点，即U-形的底端。长期本钱对许多企业而言，总本钱分为固定本钱与可变本钱取决于所考察的时间长短。在短期，一些本钱是固定的。在长期，固定本钱将变为可变的。CostsintheLongRun由于许多本钱在短期是固定的，但在长期却是可变的，因此企业的长期本钱曲线与短期本钱曲线是不同的。AverageTotalCostintheShortandLongRuns...QuantityofCarsperDay0AverageTotalCost小型工厂短期ATC

中型工厂短期ATC大型工厂短期ATC长期ATC

规模经济与规模不经济规模经济〔Economiesofscale〕指当长期平均总本钱随着产量增加而减少的特性。规模不经济〔Diseconomiesofscale〕指当长期平均总本钱随着产量增加而增加的特性。规模收益不变〔Constantreturnstoscale〕指长期平均总本钱不随产量变动而变动的特性。EconomiesandDiseconomiesofScale规模不经济QuantityofCarsperDay0AverageTotalCostATCinlongrun规模经济规模收益不变SummaryThegoaloffirmsistomaximizeprofit,whichequalstotalrevenueminustotalcost.

Whenanalyzingafirm’sbehavior,itisimportanttoincludealltheopportunitycostsofproduction.Someopportunitycostsareexplicitwhileotheropportunitycostsareimplicit.SummaryAfirm’scostsreflectitsproductionprocess.Atypicalfirm’sproductionfunctiongetsflatterasthequantityofinputincreases,displayingthepropertyofdiminishingmarginalproduct.Afirm’stotalcostsaredividedbetweenfixedandvariablecosts.Fixedcostsdon’tvarywithquantitiesproduced;variablecostsdo.SummaryAveragetotalcostistotalcostdividedbythequantityofoutput.Marginalcostistheamountbywhichtotalcostwouldriseifoutputwereincreasedbyoneunit.Themarginalcostalwaysriseswiththequantityofoutput.SummaryTheaverage-total-costcurveisU-shaped.Themarginal-costcurvealwayscrossestheaverage-total-costcurveattheminimumofATC.Afirm’scostsoftendependonthetimehorizonbeingconsidered.GraphicalReviewEconomicProfitversusAccountingProfitRevenueTotalopportunitycostsHowanEconomistViewsaFirmExplicitcostsEconomicprofitImplicitcostsExplicitcostsAccountingprofitHowanAccountantViewsaFirmRevenueAProductionFunction...QuantityofOutput(cookiesperhour)150140130120110100908070605040302010NumberofWorkersHired012345ProductionfunctionTotal-CostCurve...TotalCost$8070605040302010QuantityofOutput(cookiesperhour)020401401201008060Total-costcurveTotal-CostCurve...$0.00$2.00$4.00$6.00$8.00$10.00$12.00$14.00$16.00024681012QuantityofOutput(glassesoflemonadeperhour)TotalCostTotal-costcurveAverage-CostandMarginal-CostCurves...ATCAVCMC$0.00$0.50$1.00$1.50$2.00$2.50$3.00$3.50024681012QuantityofOutput(glassesoflemonadeperhour)

CostsAFCCostCurvesandTheirShapes$0.00$0.50$1.00$1.50$2.00$2.50024681012QuantityofOutput(glassesoflemonadeperhour)CostsMCCostCurvesandTheirShapes$0.00$0.50$1.00$1.50$2.00$2.50$3.00$3.50024681012QuantityofOutput(glassesoflemonadeperhour)TotalCostsATCRelationshipBetweenMarginalCostandAverageTotalCostMCATC$0.00$0.50