经济学原理之应用税收得成本Application:TheCostsofTaxation应用:税收的本钱Chapter8Application:TheCostsofTaxationWelfareeconomicsisthestudyofhowtheallocationofresourcesaffectseconomicwell-being.Buyersandsellersreceivebenefitsfromtakingpartinthemarket.Theequilibriuminamarketmaximizesthetota Trade无谓损失与贸易的好处Taxescausedeadweightlossesbecausetheypreventbuyersandsellersfromrealizingsomeofthegainsfromtrade.税收引起无谓损失是因为它使买者与卖者不能实现某些贸易的好处 TheDeadweightLoss.Quantity0PriceDemandSupplyQ1PBPrice=P1withouttaxPSQ2SizeoftaxLostgainsfromtradeCosttosellersValuetobuyersReductioninquantityduetothetax无谓损失.数量0价格需求供给Q1PB没有税收P1时的价格PSQ2税收规模损失的贸易好处卖者的成本买者的评价由于税收引起的数量减少DeterminantsofDeadweightLossWhatdetermineswhetherthedeadweightlossfromataxislargeorsmall?Themagnitudeofthedeadweightlossdependsonhowmuchthequantitysuppliedandquantitydemandedrespondtochangesintheprice.That,inturn,dependsonthepriceelasticitiesofsupplyanddemand.无谓损失的决定因素什么因素决定税收的无谓损失是大还是小？无谓损失的大小决定于供給量和需求量对价格变动的反应程度。
也就是说，决定于供给和需求的价格弹性 TaxDistortionsandElasticities.税收扭曲与弹性Quantity数量PriceDemand需求Supply供给0Whensupplyisrelativelyinelastic,thedeadweightlossofataxissmall.当供给比较缺乏弹性时，税收的无谓损失小 (a)InelasticSupply(b)缺乏弹性的供给Sizeoftax税收规模TaxDistortionsandElasticities.税收扭曲与弹性Quantity数量Price价格Demand需求Supply供给0Sizeoftax税收规模Whensupplyisrelativelyelastic,thedeadweightlossofataxislarge.当供给比较富有弹性时，税收无谓损失大 (b)ElasticSupply富有弹性的供给TaxDistortionsandElasticities.税收扭曲与弹性Quantity数量Price价格Demand需求Supply供给0Whendemandisrelativelyinelastic,thedeadweightlossofataxissmall.当需求比较缺乏弹性时，税收的无谓损失小。
(c)InelasticDemand缺乏弹性的需求Sizeoftax税收规模TaxDistortionsandElasticities.税收扭曲与弹性Quantity数量Price价格Demand需求Supply供给0Sizeoftax税收规模Whendemandisrelativelyelastic,thedeadweightlossofataxislarge.当需求比较富有弹性时，税收的无谓损失大 (d)ElasticDemand富有弹性的需求DeterminantsofDeadweightLoss无谓损失的决定因素Thegreatertheelasticitiesofdemandandsupply:供给和需求的弹性越大：thelargerwillbethedeclineinequilibriumquantityand,均衡数量下降的越多，thegreaterthedeadweightlossofatax.税收的无谓损失也就越大 TheDeadweightLossDebate无谓损失的争论Someeconomistsarguethatlabortaxesarehighlydistortingandbelievethatlaborsupplyismoreelastic.一些经济学家认为劳动税引起严重扭曲，他们相信劳动供给是较为富有弹性的。
TheDeadweightLossDebateSomeexamplesofworkerswhomayrespondmoretoincentives:WorkerswhocanadjustthenumberofhourstheyworkFamilieswithsecondearnersElderlywhocanchoosewhentoretireWorkersintheundergroundeconomy(i.e.thoseengaginginillegalactivity)无谓损失的争论一些对鼓励反应较大的工人:许多可以调整工作时间长短的工人一些有第二个赚钱人的家庭许多老年人可以选择什么时候退休从事地下经济活动的工人(如从事非法活动的人)DeadweightLossandTaxRevenueasTaxesVary无谓损失和税收收入随税收变动而变动Witheachincreaseinthetaxrate,thedeadweightlossofthetaxrisesevenmorerapidlythanthesizeofthetax.随着每一次税率增加，税收无谓损失的增加要快于税收规模。
DeadweightLossandTaxRevenue.无谓损失与税收收入PBQuantity数量Q20Price价格Q1Demand需求Supply供给Taxrevenue税收收入PSDeadweightLoss无谓损失(a)SmallTax小额税Demand需求Supply供给TaxRevenue税收收入PBQuantity数量Q20Price价格Q1PSDeadweightLoss无谓损失DeadweightLossandTaxRevenue.无谓损失与税收收入(b)MediumTax中额税PBQuantity数量Q20Price价格Q1Demand需求Supply供给PSDeadweightlossDeadweightLossandTaxRevenue.无谓损失与税收收入(c)LargeTax大额税税收收入DeadweightLossandTaxRevenueForthesmalltax,taxrevenueissmall.Asthesizeofthetaxrises,taxrevenuegrows.Butasthesizeofthetaxcontinuestorise,taxrevenuefallsbecausethehighertaxreducesthesizeofthemarket.无谓损失与税收收入收小额税时，税收收入少。
随着税收规模增加，税收收入增加 但随着税收规模继续增加，税收收入反而减少，这是因为较高的税收规模减少了更多的市场规模 DeadweightLossandTaxRevenueasTaxesVary无谓损失和税收收入随着税收规模而变动(a)DeadweightLoss无谓损失DeadweightLoss无谓损失0TaxSize税收规模DeadweightLossandTaxRevenueasTaxesVary无谓损失和税收收入随着税收规模而变动(b)Revenue(theLaffercurve)税收收入拉伐曲线TaxRevenue税收收入0TaxSize税收规模DeadweightLossandTaxRevenueasTaxesVaryAsthesizeofataxincreases,itsdeadweightlossquicklygetslarger.Bycontrast,taxrevenuefirstriseswiththesizeofatax;butthen,asthetaxgetslarger,themarketshrinkssomuchthattaxrevenuestartstofall.无谓损失和税收收入随税收规模而变动随着税收规模提高，无谓损失迅速增大。
相反，随着税收规模提高，税收收入先是增加，然后随着税收规模越来越大，市场规模收缩非常之大，以至于收入开始减少 TheLafferCurveandSupply-SideEconomicsTheLaffercurvedepictstherelationshipbetweentaxratesandtaxrevenue.Supply-sideeconomicsreferstotheviewsofReaganandLafferwhoproposedthatataxcutwouldinducemorepeopletoworkandtherebyhavethepotentialtoincreasetaxrevenues.拉伐曲线与供给学派经济学拉伐曲线说明税率和税收之间的关系 供给学派经济学是指里根和拉伐的观点，他们认为减税能鼓励更多的人工作，或许甚至可能增加税收 Summary小结Ataxonagoodreducesthewelfareofbuyersandsellersofthegood.Andthereductioninconsumerandproducersurplususuallyexceedstherevenuesraisedbythegovernment.向一种物品征税减少了该物品买者与卖者的福利，而且消费者和生产者剩余的减少通常超过了政府筹集到的收入。
Summary小结Thefallintotalsurplusthesumofconsumersurplus,producersurplus,andtaxrevenueiscalledthedeadweightlossofthetax.总剩余消费者剩余、生产者剩余和税收收入之和的减少被称为税收的无谓损失 SummaryTaxeshaveadeadweightlossbecausetheycausebuyerstoconsumelessandsellerstoproduceless.Thischangeinbehaviorshrinksthesizeofthemarketbelowthelevelthatmaximizestotalsurplus.小结税收有无谓损失是因为它引起买者少消费和卖者少生产 这种行为变化使市场规模缩小到使总剩余最大化的水平之下 SummaryAsataxgrowslarger,itdistortsincentivesmore,anditsdeadweightlossgrowslarger.Taxrevenuefirstriseswiththesizeofatax.Eventually,however,alargertaxreducestaxrevenuebecauseitreducesthes。