曼昆微观经济学英文版13costs_production

5FIRMBEHAVIORANDTHEORGANIZATIONOFINDUSTRYCopyright©2004South-Western13TheCostsofProductionCopyright©2004South-Western/TheMarketForcesofSupplyandDemand•Supplyanddemandarethetwowordsthateconomistsusemostoften.•Supplyanddemandaretheforcesthatmakemarketeconomieswork.•Modernmicroeconomicsisaboutsupply,demand,andmarketequilibrium.Copyright©2004South-Western/WHATARECOSTS?•AccordingtotheLawofSupply:•Firmsarewillingtoproduceandsellagreaterquantityofagoodwhenthepriceofthegoodishigh.•Thisresultsinasupplycurvethatslopesupward.Copyright©2004South-Western/WHATARECOSTS?•TheFirm’sObjective•Theeconomicgoalofthefirmistomaximizeprofits.Copyright©2004South-Western/TotalRevenue,TotalCost,andProfit•TotalRevenue•Theamountafirmreceivesforthesaleofitsoutput.•TotalCost•Themarketvalueoftheinputsafirmusesinproduction.Copyright©2004South-Western/TotalRevenue,TotalCost,andProfit•Profitisthefirm’stotalrevenueminusitstotalcost.Profit=Totalrevenue-TotalcostCopyright©2004South-Western/CostsasOpportunityCosts•Afirm’scostofproductionincludesalltheopportunitycostsofmakingitsoutputofgoodsandservices.•ExplicitandImplicitCosts•Afirm’scostofproductionincludeexplicitcostsandimplicitcosts.•Explicitcostsareinputcoststhatrequireadirectoutlayofmoneybythefirm.•Implicitcostsareinputcoststhatdonotrequireanoutlayofmoneybythefirm.Copyright©2004South-Western/EconomicProfitversusAccountingProfit•Economistsmeasureafirm’seconomicprofitastotalrevenueminustotalcost,includingbothexplicitandimplicitcosts.•Accountantsmeasuretheaccountingprofitasthefirm’stotalrevenueminusonlythefirm’sexplicitcosts.Copyright©2004South-Western/EconomicProfitversusAccountingProfit•Whentotalrevenueexceedsbothexplicitandimplicitcosts,thefirmearnseconomicprofit.•Economicprofitissmallerthanaccountingprofit.Figure1EconomicversusAccountantsCopyright©2004South-WesternRevenueTotalopportunitycostsHowanEconomistViewsaFirmHowanAccountantViewsaFirmRevenueEconomicprofitImplicitcostsExplicitcostsExplicitcostsAccountingprofitTable1AProductionFunctionandTotalCost:HungryHelen’sCookieFactoryCopyright©2004South-WesternCopyright©2004South-Western/PRODUCTIONANDCOSTS•TheProductionFunction•Theproductionfunctionshowstherelationshipbetweenquantityofinputsusedtomakeagoodandthequantityofoutputofthatgood.Copyright©2004South-Western/TheProductionFunction•MarginalProduct•Themarginalproductofanyinputintheproductionprocessistheincreaseinoutputthatarisesfromanadditionalunitofthatinput.Copyright©2004South-Western/TheProductionFunction•DiminishingMarginalProduct•Diminishingmarginalproductisthepropertywherebythemarginalproductofaninputdeclinesasthequantityoftheinputincreases.•Example:Asmoreandmoreworkersarehiredatafirm,eachadditionalworkercontributeslessandlesstoproductionbecausethefirmhasalimitedamountofequipment.Figure2HungryHelen’sProductionFunctionCopyright©2004South-WesternQuantityofOutput(cookiesperhour)150140130120110100908070605040302010NumberofWorkersHired012345ProductionfunctionCopyright©2004South-Western/TheProductionFunction•DiminishingMarginalProduct•Theslopeoftheproductionfunctionmeasuresthemarginalproductofaninput,suchasaworker.•Whenthemarginalproductdeclines,theproductionfunctionbecomesflatter.Copyright©2004South-Western/FromtheProductionFunctiontotheTotal-CostCurve•Therelationshipbetweenthequantityafirmcanproduceanditscostsdeterminespricingdecisions.•Thetotal-costcurveshowsthisrelationshipgraphically.Table1AProductionFunctionandTotalCost:HungryHelen’sCookieFactoryCopyright©2004South-WesternFigure3HungryHelen’sTotal-CostCurveCopyright©2004South-WesternTotalCost$8070605040302010QuantityofOutput(cookiesperhour)0102030150130110907050401401201008060Total-costcurveCopyright©2004South-Western/THEVARIOUSMEASURESOFCOST•Costsofproductionmaybedividedintofixedcostsandvariablecosts.Copyright©2004South-Western/FixedandVariableCosts•Fixedcostsarethosecoststhatdonotvarywiththequantityofoutputproduced.•Variablecostsarethosecoststhatdovarywiththequantityofoutputproduced.Copyright©2004South-Western/FixedandVariableCosts•TotalCosts•TotalFixedCosts(TFC)•TotalVariableCosts(TVC)•TotalCosts(TC)•TC=TFC+TVCTable2TheVariousMeasuresofCost:ThirstyThelma’sLemonadeStandCopyright©2004South-WesternCopyright©2004South-Western/FixedandVariableCosts•AverageCosts•Averagecostscanbedeterminedbydividingthefirm’scostsbythequantityofoutputitproduces.•Theaveragecostisthecostofeachtypicalunitofproduct.Copyright©2004South-Western/FixedandVariableCosts•AverageCosts•AverageFixedCosts(AFC)•AverageVariableCosts(AVC)•AverageTotalCosts(ATC)•ATC=AFC+AVCCopyright©2004South-Western/AverageCostsAFCFCQFixedcostQuantityAVCVCQVariablecostQuantityATCTCQTotalcostQuantityTable2TheVariousMeasuresofCost:ThirstyThelma’sLemonadeStandCopyright©2004South-WesternCopyright©2004South-Western/FixedandVariableCosts•MarginalCost•Marginalcost(MC)measurestheincreaseintotalcostthatarisesfromanextraunitofproduction.•Marginalcosthelpsanswerthefollowingquestion:•Howmuchdoesitcosttoproduceanadditionalunitofoutput?Copyright©2004South-Western/MarginalCostMCTCQ(changeintotalcost