微观经济学 微观经济学第二次答疑Chapter 4

ThesecondTutorialClassforChapter4DeliveredbyXiangZhangThesecondTutorialClassSomeAdviceConceptsandproofExerciseAttachmentsⅠ.Somesuggestions①答疑的自愿性；（综合因素、频率）②邮件的规范性；（换位思考、细节）③课后的自觉性；（主动提问、证明）④画图的习惯性；（简洁高效、思路）⑤笔记的及时性；（范例笔记、特色）⑥参与的差异性.(课件中的、口头）笔记范例笔记范例Ⅱ.Concepts1.价格弹性的定义、类型2.商品需求弹性大小的影响因素3.弹性的计算（1）点弹性（2）两点之间的弹性(弧弹性)4.弹性和收益的关系5.弹性与斜率间的关系6.供给弹性大小的影响因素7.税收归宿的计算8.丰收悖论（谷贱伤农）最低下限和最高上限7PriceElasticityForAVarietyofProductsThegreaterthenumberofsubstitutesforagood,themoreelasticitsdemandwillbe.ProportionOfIncomeProductDefinitionTime：Long-RunandShort-Run点弹性的计算（DD线）PQDDAZBCEO点弹性的计算（SS线）点弹性计算的三个公式：

①ED=；

②ED=P/kQ;(P=a-kQ);

③ED=k1*k2；(切线割线)税收归宿的计算

（弹性与税负承担者的关系）Taxation11P$65432105 10 15 20 25Price(perbottle)Assumethatthegovernmentleviesataxofof$1perbottle.Whatistheincidenceofthistax?StTax$1Quantity(millionsofbottlespermonth)D12P$65432105 10 15 20 25Quantity(millionsofbottlespermonth)Price(perbottle)Tax$1TaxpaidbyconsumersTaxpaidbyproducersDSSt13BroccoliCigarettesrelativelyelasticrelativelyinelasticPPQQ0PPDbDcSSTaxStProducersbearmostoftaxburden.PeTaxStPiMostofthetaxisshiftedtoconsumers14SupplyElasticityPQ0PDbSPQ0PDbSInwhichmarketissupplymoreelastic?Inwhichcasewillproducersbearmostoftheburdenofthetax?TaxStPeConsumersbearmostofthetaxTaxStPiProducersbearmostofthetax15DeadweightLossNow,weintroducedtheconceptofdeadweightlosstoillustratethelossofeconomicefficiencyfrommonopoly.

Infact,weencounterthesamedeadweightlossproblemwhenweintroduceataxintothefreemarket.16P$65432105 10 15 20 25Price(perbottle)Tax$1Canyouidentifytheefficiencyloss?Canyouidentifytheamountoftaxrevenuespaidbyconsumersandtheamountpaidbyproducers?Quantity(millionsofbottlespermonth)DBATaxpaidbyconsumersTaxpaidbyproducersEfficiencyLoss17Inwhichmarketisthedeadweightsmaller?PPDbSDcBroccoliCigarettesSTaxTaxStStPePiPqPbThedeadweightlossismuchsmallerwhendemandisinelastic.18SupplyElasticityPQ0PDbSPQ0PDbSTaxStPeConsumersbearmostofthetaxTaxStPiProducersbearmostofthetax19TheimpositionofaTaxLetPr

bethepricereceivedbyproducers

Pp

bethepricepaidbyconsumersTheproducerspaythequantitytax

Pp=Pr+tTheconsumerspaythequantitytax

Pp–t=PrTheimpositionofaTaxPassingalongthetaxSpecialcasesDeadweightLosspD(p),S(p)Market

demandMarket

supplyp*q*NotaxCSPSDeadweightLosspD(p),S(p)Market

demandMarket

supplyp*q*$tppqtprCSPSTaxDeadweightlossDeadweightLossandElasticitiespD(p),S(p)Market

demandMarket

supplyp*q*$tpbqtpsDeadweightlossDeadweightLossandElasticitiespD(p),S(p)Market

demandMarket

supplyp*q*$tpbqtpsDeadweightlossfallsasmarketdemandbecomeslessown-priceelastic.DeadweightLossandElasticitiespD(p),S(p)Market

demandMarket

supplyps=p*$tpbqt=q*WheneD=0,thetaxcausesnodeadweightloss.DeadweightLossandElasticitiesDeadweightlossduetoaquantitytaxrisesaseithermarketdemandormarketsupplybecomesmoreown-priceelastic.IfeithereD=0oreS=0thenthedeadweightlossiszero.Paretoefficiencyefficientoutputiswheredemandequalssupplybecausethatiswheredemandpriceequalssupplypricethatis,themarginalwillingnesstobuyequalsthemarginalwillingnesstoselldeadweightlossmeasures

lossduetoinefficiencyEffectsofaMinimumWagePriceControlsProduceShortages需求价格弹性（需求弹性）需求量的变化率/价格的变化率

（需求弹性>0为吉芬商品）需求收入弹性需求量的变化率/收入的变化率（>1奢侈品；>0,<1必需品；<0劣等品）需求交叉弹性

A需求量的变化率/B价格的变化率（>0替代品，<0互补品）三种需求弹性及商品分类increaseinincomeincreasesdemand—normalgoodincreaseinincomedecreasesdemand—inferiorgoodNormalgoodcanbealsodividedintoluxurygoodandnecessarygood:luxurygood:demandgoesupbyagreaterproportionthanincomenecessarygood:demandgoesupbyalesserproportionthanincomedecreaseinpriceincreasesdemand—ordinarygooddecreaseinpricedecreasesdemand—GiffengoodⅢ.Exercise①学习指南；②英文练习题；36在商品X市场中有10000个相同的个人，需求函数均为d=12-2P；同时又有1000个相同的生产者，每个生产者的供给函数均为s=20P（1）推导商品X的市场需求和供给曲线，以及均衡点（2）假设每个消费者的收入有所增加，个人需求曲线向右移动2个单位，求此时的市场需求和均衡价格数量37（3）假设每个生产者生产技术水平有了提高，个人供给曲线向右移动40个单位，求此时的市场供给函数和均衡价格数量（4）假设政府对售出的每单位商品征收2美元的销售税，请问谁承担了较大的税收？政府征收的总税额为多少（5）假设政府对生产出的每单位商品X给与1美元的补贴，消费者能否从中获得好处？均衡价格和数量是多少Ⅳ.Attachments慢慢地di