管理經(jīng)濟(jì)學(xué)第二章02需求、供給與市場(chǎng)均衡

1Chapter2需求、供給與市場(chǎng)均衡Demand,Supply,andMarketEquilibrium2Demand,Supply,andMarketEquilibrium2.1需求2.2供給2.3市場(chǎng)均衡2.4市場(chǎng)交易的價(jià)值2.5市場(chǎng)均衡的變動(dòng)2.6限制價(jià)與支持價(jià)32.1Demand(需求)Quantitydemanded(Qd)（需求量）Amountofagoodorserviceconsumersarewilling&abletopurchaseduringagivenperiodoftime一個(gè)特定時(shí)期內(nèi)，消費(fèi)者對(duì)一種商品，愿意而且能夠購(gòu)買的數(shù)量。42.1.1GeneralDemandFunction（廣義需求函數(shù)）SixvariablesthatinfluenceQdPriceofgoodorservice(P)esofconsumers(M)Pricesofrelatedgoods&services(PR)Expectedfuturepriceofproduct(Pe)Numberofconsumersinmarket(N)Generaldemandfunction5。廣義需求函數(shù):六因素P,M,PR,J,Pe,N。產(chǎn)品或服務(wù)的價(jià)格消費(fèi)者的收入相關(guān)產(chǎn)品的價(jià)格消費(fèi)者的偏好預(yù)期價(jià)格消費(fèi)者的數(shù)量6GeneralDemandFunctionb,c,d,e,f,&gareslopeparametersMeasureeffectonQd

ofchangingoneofthevariableswhileholdingtheothersconstantSignofparametershowshowvariableisrelatedtoQdPositivesignindicatesdirectrelationshipNegativesignindicatesinverserelationship7GeneralDemandFunctionVariableRelationtoQdSignofSlopeParameterPPeNMPRInverseDirectDirectDirectDirectfornormalgoodsInverseforinferiorgoodsDirectforsubstitutesb=Qd/Pisnegativec=Qd/M

ispositivec=Qd/M

isnegatived=Qd/PR

ispositived=Qd/PR

isnegativef=Qd/Pe

ispositiveg=Qd/N

ispositiveInverseforcomplementse=Qd/

ispositive82.1.2DirectDemandFunction（直接需求函數(shù)）Thedirectdemandfunction,orsimplydemand,showshowquantitydemanded,Qd

,isrelatedtoproductprice,P,whenallothervariablesareheldconstant

Qd=f(P)LawofDemandQd

increaseswhenPfalls&Qd

decreaseswhenPrises,allelseconstantQd/Pmustbenegative92.1.3InverseDemandFunction（反需求函數(shù)）Traditionally,price(P)isplottedontheverticalaxis&quantitydemanded(Qd)isplottedonthehorizontalaxisTheequationplottedistheinversedemandfunction,P=f(Qd)10GraphingDemandCurvesApointonadirectdemandcurveshowseither:MaximumamountofagoodthatwillbepurchasedforagivenpriceMaximumpriceconsumerswillpayforaspecificamountofthegood11ADemandCurve(Figure2.1)122.1.4需求量的變化與需求的變化ChangeinquantitydemandedOccurswhenpricechangesMovementalongdemandcurveChangeindemandOccurswhenoneoftheothervariables,ordeterminantsofdemand,changesDemandcurveshiftsrightwardorleftward13ShiftsinDemand(Figure2.2)142.2Supply（供給）Quantitysupplied(Qs)（供給量）Amountofagoodorserviceofferedforsaleduringagivenperiodoftime15SupplySixvariablesthatinfluenceQsPriceofgoodorservice(P)Inputprices(PI)Pricesofgoodsrelatedinproduction(Pr)Technologicaladvances(T)Expectedfuturepriceofproduct(Pe)Numberoffirmsproducingproduct(F)Generalsupplyfunction

162.2.1GeneralSupplyFunction（廣義供給函數(shù)）k,l,m,n,r,&sareslopeparametersMeasureeffectonQs

ofchangingoneofthevariableswhileholdingtheothersconstantSignofparametershowshowvariableisrelatedtoQsPositivesignindicatesdirectrelationshipNegativesignindicatesinverserelationship17GeneralSupplyFunctionVariableRelationtoQsSignofSlopeParameterPPeFPIPrDirectDirectDirectInverseInverseInverseforsubstitutesk=Qs/Pispositivel=Qs/PI

isnegativem=Qs/Pr

isnegativem=Qs/Pr

ispositiver=Qs/Pe

isnegatives=Qs/F

ispositiveDirectforcomplementsn=Qs/T

ispositiveT182.2.2DirectSupplyFunction（直接供給函數(shù)）Thedirectsupplyfunction,orsimplysupply,showshowquantitysupplied,Qs

,isrelatedtoproductprice,P,whenallothervariablesareheldconstant

Qs=f(P)192.2.3InverseSupplyFunction

（反供給函數(shù)）Traditionally,price(P)isplottedontheverticalaxis&quantitysupplied(Qs)isplottedonthehorizontalaxisTheequationplottedistheinversesupplyfunction,P=f(Qs)20GraphingSupplyCurvesApointonadirectsupplycurveshowseither:MaximumamountofagoodthatwillbeofferedforsaleatagivenpriceMinimumpricenecessarytoinduceproducerstovoluntarilyofferaparticularquantityforsale21ASupplyCurve(Figure2.3)222.2.4供給量的變化與供給的變化ChangeinquantitysuppliedOccurswhenpricechangesMovementalongsupplycurveChangeinsupplyOccurswhenoneoftheothervariables,ordeterminantsofsupply,changesSupplycurveshiftsrightwardorleftward23ShiftsinSupply(Figure2.4)242.3MarketEquilibrium（市場(chǎng)均衡）Equilibriumprice&quantityaredeterminedbytheintersectionofdemand&supplycurvesAtthepointofintersection,Qd=QsConsumerscanpurchasealltheywant&producerscansellalltheywantatthe“market-clearing”orprice25MarketEquilibrium(Figure2.5)26MarketEquilibriumExcessdemand(shortage)ExistswhenquantitydemandedexceedsquantitysuppliedExcesssupply(surplus)Existswhenquantitysuppliedexceedsquantitydemanded272.4ValueofMarketExchange

（市場(chǎng)交易的價(jià)值）Typically,consumersvaluethegoodstheypurchasebyanamountthatexceedsthepurchasepriceofthegoodsEconomicvalueMaximumamountanybuyerinthemarketiswillingtopayfortheunit,whichismeasuredbythedemandpricefortheunitofthegood28MeasuringtheValueofMarketExchange(衡量市場(chǎng)交易的價(jià)值)ConsumersurplusDifferencebetweentheeconomicvalueofagood(itsdemandprice)&themarketpricetheconsumermustpayProducersurplusForeachunitsupplied,differencebetweenmarketprice&theminimumpriceproducerswouldaccepttosupplytheunit(itssupplyprice)SocialsurplusSumofconsumer&producersurplusAreabelowdemand&abovesupplyovertherelevantrangeofoutput29MeasuringtheValueofMarketExchange(Figure2.6)302.5ChangesinMarketEquilibrium（市場(chǎng)均衡的變化）QualitativeforecastPredictsonlythedirectioninwhichaneconomicvariablewillmoveQuantitativeforecastPredictsboththedirectionandthemagnitudeofthechangeinaneconomicvariable31DemandShifts(SupplyConstant)

(Figure2.7)32SupplyShifts(DemandConstant)

(Figure2.8)33SimultaneousShiftsWhendemand&supplyshiftsimultaneouslyCanpredicteitherthedirectioninwhichpricechangesorthedirectioninwhichquantitychanges,butnotbothThechangeinequilibriumpriceorquantityissaidtobeindeterminatewhenthedirectionofchangedependsontherelativemagnitudesbywhichdemand&supplyshift34SD’S’’S’DSimultaneousShifts:(D,S)QPricemayriseorfall;QuantityrisesP?AQPB?P’Q’Q’’C?P’’35DSimultaneousShifts:(D,S)SD’S’’S’QPricefalls;QuantitymayriseorfallP?AQPB?P’