微觀經(jīng)濟(jì)學(xué)：ch07 生產(chǎn)成本

Copyright?2013PearsonEducation,Inc.?Microeconomics?Pindyck/Rubinfeld,8e.*of557.1 成本測(cè)度：哪些成本重要？7.2 短期成本7.3 長(zhǎng)期成本7.4 短期成本和長(zhǎng)期成本的曲線7.5 兩種產(chǎn)品的生產(chǎn)---范圍經(jīng)濟(jì)7.6 成本的動(dòng)態(tài)變化-----學(xué)習(xí)曲線7.7 估計(jì)和預(yù)測(cè)成本Theory—AMathematicalTreatmentCHAPTER

7Preparedby:FernandoQuijano,IllustratorTheCostof

Production生產(chǎn)成本CHAPTEROUTLINE成本測(cè)度:那些成本重要?7.1●會(huì)計(jì)成本

accountingcost

Actualexpensesplusdepreciationchargesforcapitalequipment.●

經(jīng)濟(jì)成本economiccost

Costtoafirmofutilizingeconomicresourcesinproduction.●

機(jī)會(huì)成本opportunitycost

與企業(yè)為將資源用于其他可供選擇的最佳用途而放棄的機(jī)會(huì)相聯(lián)系的成本?！?/p>

沉淀成本Sunkcost已經(jīng)發(fā)生的而無(wú)法收回的支出FixedCostsandVariableCosts●總成本

totalcost(TCorC)

Totaleconomiccostofproduction,consisting

offixedandvariablecosts.●

固定成本fixedcost(FC)Costthatdoesnotvarywiththelevelofoutputandthatcanbeeliminatedonlybyshuttingdown.●

可變成本variablecost(VC)Costthatvariesasoutputvaries.Fixedcostdoesnotvarywiththelevelofoutput—itmustbepaidevenifthereisnooutput.Theonlywaythatafirmcaneliminateitsfixedcostsisbyshuttingdown.MarginalandAverageCostTABLE7.1AFIRM’SCOSTSRATEOFOUTPUT(UNITSPERYEAR)FIXEDCOST(DOLLARSPERYEAR)VARIABLECOST(DOLLARSPERYEAR)TOTALCOST(DOLLARSPERYEAR)MARGINALCOST(DOLLARSPERUNIT)AVERAGEFIXEDCOST(DOLLARSPERUNIT)AVERAGEVARIABLECOST(DOLLARSPERUNIT)AVERAGETOTALCOST(DOLLARSPERUNIT)(FC)(1)(VC)(2)(TC)(3)(MC)(4)(AFC)(5)(AVC)(6)(ATC)(7)050050————150501005050501002507812828253964350981482016.732.749.34501121621412.52840.555013018018102636650150200208.32533.3750175225257.12532.1850204254296.325.531.8950242292385.626.932.4105030035058530351150385435854.53539.5邊際成本MARGINALCOST(MC)平均成本AVERAGETOTALCOST(ATC)●

averagetotalcost(ATC)Firm’stotalcostdividedbyitslevelofoutput.●

averagefixedcost(AFC)Fixedcostdividedbythelevelofoutput.●

averagevariablecost(AVC)Variablecostdividedbythelevelofoutput.短期成本（labor）7.2(7.1)邊際報(bào)酬遞減和邊際成本

TheShapesoftheCostCurvesCostintheLongRun7.3

(7.2)●

isocostline

ChoosingInputs(givenq)INPUTSUBSTITUTIONWHENANINPUTPRICECHANGESWhenthepriceoflaborincreases,theisocostcurvesbecomesteeper.(7.3)Wecanrewritethisconditionslightlyasfollows:(7.4)

EXPANSIONPATHLONG-RUNTOTALCOSTCURVEqisincreasingLong-RunversusShort-Run

CostCurves7.4TheInflexibilityofShort-RunProductionKisfixedLong-RunAverageCost●long-runaveragecostcurve(LAC)Curverelatingaveragecostofproductiontooutputwhenallinputs,includingcapital,arevariable.●short-runaveragecostcurve(SAC)Curverelatingaveragecostofproductiontooutputwhenlevelofcapitalisfixed.●long-runmarginalcostcurve(LMC) Curveshowingthechangeinlong-runtotalcostasoutputisincreasedincrementallyby1unit.LONG-RUNAVERAGEANDMARGINALCOSTFIGURE7.9EconomiesandDiseconomiesofScaleAsoutputincreases,thefirm’saveragecostofproducingthatoutputis

likelytodecline,atleasttoapoint.Atsomepoint,however,itislikelythattheaveragecostofproduction

willbegintoincreasewithoutput.●economiesofscaleSituationinwhichoutputcanbedoubledfor

lessthanadoublingofcost.●diseconomiesofscaleSituationinwhichadoublingofoutputrequiresmorethanadoublingofcost.IncreasingReturnstoScale:Outputmorethandoubleswhenthequantitiesofallinputsaredoubled.EconomiesofScale: Adoublingofoutputrequireslessthanadoublingofcost.(7.5)(7.6)TheRelationshipbetweenShort-RunandLong-RunCost兩種產(chǎn)出—范圍經(jīng)濟(jì)和范圍不經(jīng)濟(jì)7.5●產(chǎn)品轉(zhuǎn)換曲線producttransformationcurve

givensetofinputs.●economiesofscope

范圍經(jīng)濟(jì)

當(dāng)單個(gè)企業(yè)的聯(lián)合產(chǎn)出超過(guò)各生產(chǎn)一種產(chǎn)品的兩個(gè)企業(yè)所能達(dá)到的總產(chǎn)量時(shí)，存在范圍經(jīng)濟(jì)?！馾iseconomiesofscope

范圍不經(jīng)濟(jì)如果企業(yè)的聯(lián)合產(chǎn)出低于獨(dú)立企業(yè)所能達(dá)到的總產(chǎn)量，那么其生產(chǎn)過(guò)程就是范圍不經(jīng)濟(jì)。TheDegreeofEconomiesofScope(7.7)

AppendixtoChapter7ProductionandCostTheory—AMathematicalTreatmentCostMinimization

Thecost-minimizationproblemcanbewrittenas

(A7.1)subjecttotheconstraintthatafixedoutputq0beproduced:(A7.2)

Step1:SetuptheLagrangian.

(A7.3)Step2:DifferentiatetheLagrangianwithrespecttoK,L,andλandsetequaltozero.

(A7.4)Step3:Combinethefirsttwoconditionsin(A7.4)toobtain

Rewritethefirsttwoconditionsin(A7.4toevaluatetheLagrangemultiplier:

MarginalRateofTechnicalSubstitutionWritetheisoquant:

(A.)

DualityinProductionandCostTheoryThedualproblemaskswhatcombinationofKandLwillletusproducethemostoutputatacostofC0.

Step1:SetuptheLagrangian.

Step2:DifferentiatetheLagrangianwithrespecttoK,L,andandsetequaltozero:

Step3:Combinethefirsttwoequations:

Thisisthesameresultas

thenecessaryconditionforcostminimization.TheCobb-DouglasCostandProductionFunctions●Cobb-DouglasproductionfunctionProductionfunctionofthe

formq=AKLβ,whereqistherateofoutput,Kisthequantityofcapital,andListhequantityoflabor,andwhere