chap004SupplyandDemand(M-Grow-Hill,微观经济学,王

Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/IrwinSupplyandDemandChapter4Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-2LaugherCurveQ.WhatdoyougetwhenyoucrosstheGodfatherwithaneconomist?A.Anofferyoucan'tunderstand.Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-3DemandDemandmeansthewillingnessandcapacitytopay.Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-4DemandPricesarethetoolsbywhichthemarketcoordinatesindividualdesires.Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-5TheLawofDemandQuantitydemandedrisesaspricefalls,otherthingsconstant.Quantitydemandedfallsaspricesrise,otherthingsconstant.Thus,thereisaninverserelationshipbetweenpriceandquantitydemanded.Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-6TheLawofDemandWhataccountsforthelawofdemand?PeopletendtosubstituteforgoodswhosepricehasgoneupCopyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-7TheDemandCurveThedemandcurveisthegraphicrepresentationofthelawofdemand.Thedemandcurveslopesdownwardandtotheright.Asthepricegoesup,thequantitydemandedgoesdown.Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-8TheDemandCurveTheslopetellsusthatquantitydemandedvariesindirectly—intheoppositedirection—withprice.Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-9OtherThingsConstantOtherthingsconstantmeansthatallotherfactorsthataffecttheanalysisareassumedtoremainconstant,whethertheyactuallyremainconstantornot.Thesefactorsmayincludechangingtastes,pricesofothergoods,eventheweather.Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-10DPrice(perunit)0Quantitydemanded(perunitoftime)PAQAAASampleDemandCurveCopyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-11ShiftsinDemandVersusMovementsAlongaDemandCurveDemandreferstoascheduleofquantitiesofagoodthatwillbeboughtperunitoftimeatvariousprices,otherthingsconstant.Graphically,itreferstotheentiredemandcurve.Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-12ShiftsinDemandVersusMovementsAlongaDemandCurveQuantitydemandedreferstoaspecificamountthatwillbedemandperunitoftimeataspecificprice.Graphically,itreferstoaspecificpointonthedemandcurve.Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-13ShiftsinDemandVersusMovementsAlongaDemandCurveAmovementalongademandcurveisthegraphicalrepresentationoftheeffectofachangeinpriceonthequantitydemanded.Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-14ShiftsinDemandVersusMovementsAlongaDemandCurveAshiftindemandisthegraphicalrepresentationoftheeffectofanythingotherthanpriceondemand.Theoriginalcurvewillmovetotherightortotheleft.Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-15ChangeinQuantityDemanded0D1Changeinquantitydemanded(amovementalongthecurve)BPrice(perunit)Quantitydemanded(perunitoftime)100$2$1200ACopyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-16D0D1ShiftinDemandPrice(perunit)Quantitydemanded(perunitoftime)100$2$1200BAChangeindemand(ashiftofthecurve)250Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-17ShiftFactorsofDemandShiftfactorsofdemandarethosethatcauseshiftsinthedemandcurvetotherightorleft.Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-18ShiftFactorsofDemandShiftfactorsofdemandinclude—butarenotlimited—tothefollowing:Society'sincomeThepricesofothergoodsTastesExpectationsCopyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-19ShiftFactorsofDemandAriseinincomewillincreasedemandforgoods.Whenthepricesofsubstitutegoodsfall,youwillconsumelessofthegoodwhosepricehasnotchanged.Achangeintastewillchangedemandwithnochangeinprice.Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-20ShiftFactorsofDemandIfyouexpectyourincometorise,youmayconsumemorenow.Ifyouexpectpricestofallinthefuture,youmayputoffpurchasestoday.Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-21TheDemandTableThedemandtableassumesallthefollowing:Aspricerises,quantitydemandeddeclines.Quantitydemandedhasaspecifictimedimensiontoit.Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-22TheDemandTableThedemandtableassumesallthefollowing:Alltheproductsinvolvedareidenticalinshape,size,quality,etc.Thescheduleassumesthateverythingelseisheldconstant.Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-23FromaDemandTabletoaDemandCurveYouploteachpointinthedemandtableonagraphandconnectthepointstoderivethedemandcurve.Copyright©2001byTheMcGraw-HillCompanies,Inc.Allrightsreserved.McGraw-Hill/Irwin4-24FromaDema