经济学专业英语教程（第四版-上）课件：Price Elasticities of Demand and Supply

《经济学专业英语教程（第四版·上）》

Text:PriceElasticitiesofDemandandSupply

（需求与供给的价格弹性）1.Keywords2.Priceelasticityofdemand3.Priceelasticityofsupply4.Lawofdiminishingmarginalutility5.Consumersovereignty6.TranslatethefollowingintoChinese7.Questions1.Keywordspriceelasticityofdemandpriceinelasticindemandpriceelasticindemandpriceelasticityofsupplysalestaxesnecessitiesoflifetotalrevenuediminishingmarginalutilityorsatisfactionsaturationpointallocationofresourcesderiveddemandconsumersovereignty2.Priceelasticityofdemand2.1Priceelasticityofdemand2.2Priceinelasticandelasticindemand2.3Importanceofpriceelasticityofdemand2.1PriceelasticityofdemandMeasureshowgreatlyapricechangeaffectsachangeindemand.2.2PriceinelasticandelasticindemandPriceinelasticindemandSomegoodsaresomuchindemandthathowevermuchpricesrise,thedemandforthemremainsthesameordropsoffonlyslightly.Thesegoodsarecalledpriceinelasticindemand.PriceelasticindemandOthergoods,whichareboughtreadilyiftheirpricesarelowbutareboughtinmuchsmallerquantitiesifthepricesrise,aretermedpriceelasticindemand.2.3ImportanceofpriceelasticityofdemandItisimportanttogovernmenttaxationpolicy.Ifagoodisrelativelypriceinelasticindemand,thenimposingataxonitwillnotcausesalestodropsubstantially.Ifthegovernmentintendstousesalestaxestoraiserevenue,itwouldbepointlesstoputthetaxonproductswhichareelasticindemandbecause,asthetaxcausespricestorise,consumerswillbuyanuntaxedsubstituteifthatispossible(andifitischeaper),orjustcutdownthequantitytheypurchase.Itisalsoimportanttosellersasitindicatestothemwhetheradropinpricewillresultinincreasedrevenuefromincreasedsales,orwhetheritwillmerelyresultinalossoftotalrevenue.Ifsellersraisethepricesoftheirgood,anddemandiselastic,theymaylosesales,resultinginalossoftotalrevenue.Ifdemandisinelastictheycanraisepricesandnotloserevenue.3.Priceelasticityofsupply3.1Priceelasticityofsupply3.2Priceinelasticandelasticinsupply3.1PriceelasticityofsupplyItreferstoarelativeresponsivenessofthequantitysuppliedofagoodwhenthemarketpriceofthegoodchanges.3.2PriceinelasticandelasticinsupplySupplycanalsobeinelasticinresponsetochangesinprice,particularlyifthesupplyisphysicallylimitedandcannotbegreatlyincreasedintheshortrun,nomatterwhatpriceisoffered.Supplyiselasticwhenitcanbeincreasedreadily.4.Lawofdiminishingmarginalutility4.1Definitionoflawofdiminishingmarginalutility4.2Importanceoflawofdiminishingmarginalutility4.1DefinitionoflawofdiminishingmarginalutilityConsumers’pleasureorsatisfactiondiminishesastheybuyeachextraunit,untiltheyreachsaturationpoint.Itisthisaspectofconsumerdemand,aswellasthelawofdemandthatbuyerswillbuymoreatalowerprice,whichhelpstomakethedemandcurveslopedownwardsfromlefttoright.4.2ImportanceoflawofdiminishingmarginalutilityThepricewhichbuyersarepreparedtoofferwillinducesupplierstomaketheirproductionplansonthebasisofthestrengthofthemarketforces.Ifconsumersarepreparedtopaymoreforcertaingoodsthisbehaviorisasignaltotheproducerstosupplythoseitemsinpreferencetoothersforwhichdemandisloworpricesobtainedarelow.Firmswillthereforeobtaintheresourcesneededtosatisfyconsumerdemand.Thepricemechanismindicateswhatshouldbeproduced,andthisinturnleadstotheallocationofresourcesforthatpurpose.5.ConsumersovereigntyThistermmeansthattheconsumersaresupremeandtheirdecisionsareall—importantindecidingwhatshallbeproducedandhowproductionshallbedistributed.Insuchapurelycompetitivemarket,theconsumerhascontroloverthewayinwhichtheeconomicproblemissolvedandovertheproductiondecisionsmade.Economicchoicesinthissystemaremadepurelythroughthemarketmechanismasitreactstopeople’sdemands.Thiskindofsituationisonlypartlytrueofamoderncapitalisteconomy,inwhichconsumerscanchooseonlybetweenthoseitemswhichareoffered.Theiralternativesarelimited.6.TranslatethefollowingintoChinese(1)Somegoodsaresomuchindemandthathowevermuchpricesrise,thedemandforthemremainsthesameordropsoffonlyslightly.(2)Theconceptofelasticityofdemandisimportanttosellersasitindicatestothemwhetheradropinpricewillresultinincreasedrevenuefromincreasedsales,orwhetheritwillmerelyresultinalossoftotalrevenue.(3)Asthepurchaseofeachchocolatebargiveslesspleasurethantheonebefore,itmakesmoresensetousethemoneyforsomethingwhichgivesgreatersatisfaction.(4)Ifconsumersarepreparedtopaymoreforcertaingoodsthisbehaviorisasignaltotheproducerstosupplythoseitemsinpreferencetoothersforwhichdemandisloworpricesobtainedarelow.7.Qu