微观经济学英文课件Ch-04

TheMarketForcesofSupplyandDemand供给与需求的市场力量Chapter4TheMarketForcesofSupplyandDemand•SupplyandDemandarethetwowordsthateconomistsusemostoften.–供给和需求是经济学家最常用的两个术语。•SupplyandDemandaretheforcesthatmakemarketeconomieswork.–供给和需求即是推动市场经济运行的力量所在•Modernmicroeconomicsisaboutsupply,demandandequilibrium.–现代微观经济学研究供给、需求和均衡。Markets市场•Amarketisagroupofbuyersandsellersofaparticulargoodorservice.市场是由某个商品或服务的买者和买者组成的群体•Thetermssupplyanddemandrefertothebehaviorofpeople…astheyinteractwithoneanotherinmarkets.术语供给和需求指人们的行为——当他们在市场中相互作用时。•Thebuyersasagroupdeterminethedemand.–买方作为一个整体决定需求•Thesellersasagroupdeterminethesupply.–卖方作为一个整体决定供给MarketType市场类型Acompetitivemarketisamarketinwhich竞争性市场是指这样的市场：•…withmanybuyersandmanysellers–有许多的买者和卖者•…thatisnotcontrolledbyanyoneperson–市场不受任何一个人操纵•…inwhichanarrowrangeofpricesareestablishedthatbuyersandsellersactupon.–买者和卖者所遵循的价格被约束在窄小的范围内。Competition:Perfectandotherwise竞争：完全竞争与否Perfectcompetition:完全竞争•Productsareallthesame–产品完全相同•Numerousbuyersandsellerssothateachhasnoinfluenceovertheprice–有无数的卖者和买者以至与任何人不能影响价格•Buyersandsellersarepricetakers–买者和买者都是价格接受者•Noentrybarriers…–没有进入壁垒Competition:Perfectandotherwise竞争：完全竞争与否•Monopoly:完全垄断–Oneseller,sellercontrolsprice一个卖者，买者控制价格•Oligopoly:寡头垄断–Fewsellers少数几个卖者–Notalwaysaggressivecompetition竞争不一定总是很激烈。•MonopolisticCompetition:垄断竞争−Manysellers许多卖者−Slightlydifferentiatedproducts产品有微小差别−Eachsellermaysetpriceforitsownproduct每一个卖者都能为自己的产品设定价格。Demand需求•Quantitydemandedistheamountofagoodthatbuyersarewillingandabletopurchase.–需求量是买者愿意且能够购买的量•TheLawofDemandstatesthat,ceterisparibus,thereisaninverserelationshipbetweenpriceandquantitydemanded(GiffenGoods).–需求法则是说，其他条件不变的情况下，价格和需求量负相关（吉芬商品）•CeterisparibusisaLatinphrasethatmeansallvariablesotherthantheonesbeingstudiedareassumedtobeconstant.Literally,itmeansotherthingsbeingequal.–CeterisParibus是一个拉丁习词，指除了被研究的变量外，其他变量都假定是不变的。DemandScheduleandCurve$3.002.502.001.501.000.50213456789101211PriceofIce-CreamConeQuantityofIce-CreamCones0PriceQuantity$0.00120.50101.0081.5062.0042.5023.000MarketDemand市场需求•Markerdemandreferstothesumofallindividualdemandsforaparticulargoodorservice.–市场需求是所有个人对某个商品或服务的需求总和。•Graphically,individualdemandcurvesaresummedhorizontallytoobtainthemarketdemandcurve.–从图形上看，将个人需求曲线水平加总就得到了市场需求曲线。TheMarketDemandCurvePriceofIce-CreamConePriceofIce-CreamConePriceofIce-CreamCone2.002.002.004371.001.001.008513QuantityofIce-CreamConesQuantityofIce-CreamConesQuantityofIce-CreamConesCatherine’sDemandNicholas’sDemandMarketDemand+=Whenthepriceis$2.00,Catherinewilldemand4ice-creamcones.Whenthepriceis$2.00,Nicholaswilldemand3ice-creamcones.Themarketdemandat$2.00willbe7ice-creamcones.Whenthepriceis$1.00,Catherinewilldemand8ice-creamcones.Whenthepriceis$1.00,Nicholaswilldemand5ice-creamcones.Themarketdemandat$1.00,willbe13ice-creamcones.Themarketdemandcurveisthehorizontalsumoftheindividualdemandcurves!DeterminantsofDemand需求的决定因素•Markerprice市场价格•Consumerincome消费者收入•Pricesofrelatedgoods相关商品的价格•Tastes偏好•Expectations预期•Population人口ChangeinQuantityDemandedvs.ChangeinDemand•ChangeinQuantityDemanded需求量的变化–Movementalongthedemandcurve.沿着需求曲线–Causedbyachangeinthepriceoftheproduct.由商品价格变化导致•ChangeinDemand需求的变化–Ashiftinthedemandcurve,eithertotheleftorright.需求曲线发生移动：左移或右移–Causedbyachangeinadeterminantotherthantheprice.由除了价格以外的影响需求的其他因素变化导致ChangesinQuantityDemanded0D1PriceofCigarettesperPackNumberofCigarettesSmokedperDayAtaxthatraisesthepriceofcigarettesresultsinamovementalongthedemandcurve.AC202.00$4.0012ChangesinDemand0D1PriceofIce-CreamConeQuantityofIce-CreamConesD3D2IncreaseindemandDecreaseindemandConsumerIncome•Asincomeincreasesthedemandforanormalgoodwillincrease.–随着收入的增加，对正常品的需求会增加•Necessaries必需品•Luxuries奢侈品•Asincomeincreasesthedemandforaninferiorgoodwilldecrease.–随着收入的增加，对劣等品的需求会减少ConsumerIncomeNormalGood$3.002.502.001.501.000.50213456789101211PriceofIce-CreamConeQuantityofIce-CreamCones0IncreaseindemandAnincreaseinincome...D1D2ConsumerIncomeInferiorGood$3.002.502.001.501.000.50213456789101211PriceofIce-CreamConeQuantityofIce-CreamCones0DecreaseindemandAnincreaseinincome...D1D2PricesofRelatedGoodsSubstitutes&Complements•Whenafallinthepriceofonegoodreducesthedemandforanothergood,thetwogoodsarecalledsubstitutes.–如果一个商品的价格下降会减少另外一个商品的需求，则这两种商品称为替代品。•Whenafallinthepriceofonegoodincreasesthedemandforanothergood,thetwogoodsarecalledcomplements.–如果一个商品的价格下降会增加另外一个商品的需求，则这两种商品称为互补品。ChangeinQuantityDemandedversusChangeinDemandVariablesthatAffectQuantityDemandedAChangeinThisVariable...PriceRepresentsamovementalongthedemandcurveIncomeShiftsthedemandcurvePricesofrelatedgoodsShiftsthedemandcurveTastesShiftsthedemandcurveExpectationsShiftsthedemandcurveNumberofbuyersShiftsthedemandcurveSupply供给•Quantitysuppliedistheamountofagoodthatsellersarewillingandabletosell.–供给量是指一个商品的销售者愿意且能够销售的数量。•TheLawofSupplystatesthatthereisapositiverelationshipbetweenpriceandquantitysupplied.(land,relics,superstar)–供给法则是指价格和供给量正相关（土地、遗迹、超级明星）SupplyCurve$3.002.502.001.501.000.50213456789101211PriceofIce-CreamConeQuantityofIce-CreamCones0PriceQuantity$0.0000.5001.00