生产函数决定成本函数(ppt 37)英文版

©2005byThomsonSouth-Western,partoftheThomsonCorporation.Allrightsreserved.•生產函數決定成本函數，而(邊際)成本會影響供給函數；因此，本章先介紹生產函數，然後說明成本函數。•生產函數在說明生產要素與產量之間的關係；生產要素分為兩類，一類是短期即可變動其使用的數量的(以勞工為代表)，另一類是長期才可變動其使用的數量的(以資本為代表)。•產量受到生產技術與生產要素的影響•Wheredocostcurvescomefrom•Dependsonfirm’savailabletechnology•Determinesproductionprocess•Productionprocessdeterminesfirm’scosts•Limitedoptionsinshortrun(SR)•Initialassumption–Firmcanhiremorelabor•Totalproduct(TP)oflabor–Quantityofoutputproducedbyfirminagivenamountoftimedependentonlaborhired–Informationgraphicallyrepresentedbyproductionfunction•Productionfunctionslopesupward•Productionfunctionisrulefordetermininghowmuchoutputcanbeproducedwithagivenbasketofinputs•Marginalproductoflabor(MPL)–Increaseintotalproductbasedonhiringoneadditionalworker–Assumecapitalfixed–SlopeofTP•Averageproductoflabor(APL)–Totalproductdividedbynumberofworkers精品资料网CalculatingMPandAP),(,),,(LKfQTPdLdQdLdTPMPLLQLTPAPLLKfQTP長期短期00,2精品资料网Landsburg,PriceTheoryandApplication,6thedition10ShapeofMPandAPCurves•AP–Ifnumberofworkerslarge,additionalworkerscauseaverageproductoflabortodecrease–InvertedU-shape•MP–InvertedU-shape•APandMPrelationshiptooneanother–IfMPAP,MPliesaboveAP–IfMPAP,MPliesbelowAP–IfMP=AP,APatmaximumorpeak精品资料网Landsburg,PriceTheoryandApplication,6thedition12VariableCostsintheSR•Constructingthefirm’svariablecostcurve–Needtotalproductcurve–Needwagerate•Priceofhiringlabor–MultiplynumberofworkersbywageratetogetvariablecostPL×L=VC–Curverelatestotalproduct,notnumberofworkers,tovariablecost精品资料网Landsburg,PriceTheoryandApplication,6thedition14EXHIBIT6.3VariableCostCurve•Costsofcapital–Physicalassets,suchasmachineryandfactories–Ex.handyman’svan•TotalcostequaltosumoffixedandvariablecostsofproductionTC=FC+VC=FC+PL×L•Additionalcostconsiderationsbesidetotals•Averagevariablecost(AVC):variablecostdividedbyquantityofoutput–Laboronlyvariablefactorofproduction•CalculateAVCbytakingthewagerateanddividingbyAPL•Averagecost(AC):totalcostdividedbyquantityofoutput–Sometimescalledaveragetotalcost•Marginalcost(MC):additionalcostattributabletothelastunitofoutputproduced–Laboronlyvariablefactorofproduction•CalculateMCbytakingthewagerateanddividingbyMPL)()()()()(短期精品资料网Landsburg,PriceTheoryandApplication,6thedition20MC&ACACMCQQTCdQdTCQTCdQdTCQdQQTCddQdACQTCACdQdTCMC00,2•VCcurvealwaysincreasing–Moreoutputrequiresmorelabor–Highercosts•TCcurvedeterminedbysumofFCandVC–FCconstant–HassameshapeasVCcurve•MC,AC,andAVCcurvesareU-shaped精品资料网Landsburg,PriceTheoryandApplication,6thedition23CostCurvesRelations•MCrelationshiptoAVCandAC–MCbelowAVC,AVCfalling–MCaboveAVC,AVCrising–MCequalsAVC,AVCatminimum–CanreplaceAVCwithAC,sameholdstrue•Shapesofcostcurvesrelatedtoshapesofproductcurves•Inlongrun(LR),firmcanadjustemploymentofcapitalandlabor•Attemptstoachievetheleastcostmethodofproducingagivenquantityofoutput•GeometryofLRproduction–LabelverticalaxiswithK,standsforcapital–LabelhorizontalaxiswithL,whichstandsforlabor–Fixedperiodoftime•Wanttouseleastcostlymethod–Avoi