Chapter_08

第八章应用：税收的代价Application:The Costs of Taxation1税收的代价The Costs of Taxation税收如何影响市场参与者的福利？How do taxes affectthe economic well-being of marketparticipants?2税收的代价The Costs of Taxation向买者征税和向卖者征税是无关的。

当征税时，买者支付的价格上升，而卖者得到的价格下降。

It does notmatter whether a tax on agood is levied on buyers orsellers of the good…the pricepaid by buyers rises, and theprice received by sellers falls.34税收的影响The Effects of a Tax...Price 0Quantity无税收时的数量Quantitywithout tax SupplyDemand没有税收时的价格Pricewithout tax买者支付的价格Price buyers pay 有税收时的数量Quantity with tax 税收规模Size of tax卖者得到的价格Pricesellersreceive税收的影响The Effects of a Tax税收在买者支付的价格和卖者得到的价格之间加入一个楔子A tax places a wedge between the price buyers pay and the price sellers receive.由于这个楔子，卖出的数量低于如果没有税收时的数量Because of this tax wedge, the quantity sold falls below the level that would be sold without a tax.市场规模因此而缩小The size of the market for that good shrinks.5税收收入Tax RevenueT = 税收规模the size of the taxQ = 销售量the quantity of the good sold T×Q = 政府税收收入the government’s tax revenue67税收收入Tax Revenue...Price 0QuantityQuantity without tax SupplyDemandPrice sellers receiveQuantity with tax 税收规模Size of tax (T)销售数量Quantity sold (Q)税收收入TaxRevenue (T x Q)Price buyers pay8税收如何影响福利How a Tax Affects Welfare...Quantity 0Price DemandSupplyQ 1A B CFD E Q 2税收减少消费者剩余(B+C)和生产者剩余(D+E)Tax reduces consumer surplus by (B+C) andproducer surplus by (D+E)税收收入Tax revenue = (B+D)无谓损失Deadweight Loss = (C+E)Price buyers pay =P BP 1Price withouttax =P SPrice sellers receive =税收导致的福利变化Changes in Welfarefrom a Tax没有税收时Without Tax有税收时With Tax变化Change 消费者剩余Consumer Surplus A + B + C A-(B+C)生产者剩余Producer Surplus D + E + F F-(D + E)税收收入Tax Revenue none B + D+ (B + D)总剩余Total Surplus A + B + C + D + E + F A + B + D + F-(C + E )面积C+E衡量了总剩余的减少，它是税收的无谓损失The area C+E shows the fall in total surplus and isthe deadweight loss of the tax.9税收如何影响福利How a Tax Affects Welfare总福利的变化包括：The change in total welfare includes:消费者剩余的变化The change in consumer surplus生产者剩余的变化The change in producer surplus税收收入的变化The change in tax revenue.买者和卖者的损失超过政府的税收收入The losses to buyers and sellers exceed the revenueraised by the government.这种总剩余的下降被称为无谓损失，这是效率的损失This fall in total surplus is called the deadweight loss. 这被称为税收扭曲This is called tax distortion10无谓损失和贸易的好处Deadweight Losses and the Gains from Trade税收引起的无谓损失是因为它使买者和卖者不能实现某些贸易的好处Taxes cause deadweight losses because they prevent buyers and sellers from realizing some of the gains from trade.1112无谓损失The Deadweight Loss...Quantity0Price DemandSupplyQ 1P B 没有税收时的价格Price = P 1without tax P SQ 2税收规模Size of tax损失的贸易好处Lost gainsfrom trade卖者的成本Cost to sellers买者的价值Value to buyers 由于税收引起的数量减少Reduction inquantity due to the tax补贴Subsidy¾补贴的方式有三种：对生产者补贴、对消费者补贴或者对两者各补贴一部分。

¾我们需要知道的是这三种不同的补贴的经济结果有何不同。

13补贴Subsidy对生产者补贴一块钱卖者得到的价格买者支付的价格14补贴Subsidy•经济后果¾市场规模扩大¾买者支付的价格降低；卖者得到的价格升高15补贴Subsidy对消费者补贴一块钱卖者得到的价格买者支付的价格16补贴Subsidy•经济后果¾对卖者和买者补贴，经济结果是完全相同的。

即相当于在买者支付的价格和卖者得到的价格之间打入一个楔子。

（记住这个楔子和税收的楔子正好反向）17补贴的无谓损失Deadweight loss of Subsidy补贴楔子1819补贴的无谓损失Deadweight loss of Subsidy补贴楔子三角形A 三角形B 总的消费者剩余的增加是图中蓝色梯形政府的补贴额是图中蓝色梯形+青色三角无谓损失的决定因素Determinants of Deadweight Loss 什么因素决定税收的无谓损失是大还是小？What determines whether the deadweight loss froma tax is large or small?无谓损失的量取决于供给量和需求量对价格变动的反应程度The magnitude of the deadweight loss depends on how much the quantity supplied and quantitydemanded respond to changes in the price.它又取决于供给和需求的价格弹性That, in turn, depends on the price elasticities ofsupply and demand.2021税收扭曲和弹性Tax Distortions and ElasticitiesQuantityPrice DemandSupply0当供给比较缺乏弹性时,税收的无谓损失小When supply is relatively inelastic,the deadweight lossof a tax is small.(a) 缺乏弹性的供给Inelastic Supply税收规模Size of tax22税收扭曲和弹性Tax Distortions and ElasticitiesQuantityPrice DemandSupply0税收规模Sizeof tax当供给比较富有弹性时,税收的无谓损失大When supply is relatively elastic,the deadweight loss of a tax is large.(b) 富有弹性的供给ElasticSupply23税收扭曲和弹性Tax Distortions and ElasticitiesQuantityPrice DemandSupply0当需求比较缺乏弹性时,税收的无谓损失小When demand is relatively inelastic,the deadweight loss of a tax is small.(c)缺乏弹性的需求Inelastic Demand税收规模Size of tax24税收扭曲和弹性Tax Distortions and Elasticities QuantityPrice Demand Supply0Size of tax当需求比较富有弹性时,税收的无谓损失大When demand is relatively elastic,the deadweight loss of a tax is large.(d)富有弹性的需求Elastic Demand无谓损失的决定因素Determinants of Deadweight Loss 需求和供给的弹性越大:The greater the elasticities of demand and supply:均衡数量的的减少就越大the larger will be the decline in equilibrium quantity and,税收的无谓损失就越大the greater the deadweight loss of a tax.25无谓损失的争论The Deadweight Loss Debate 一些经济学家认为劳动税是严重扭曲的，因为他们相信劳动供给较为富有弹性Some economists argue that labor taxes are highly distorting and believe that labor supply is more elastic.26无谓损失的争论The Deadweight Loss Debate工人对激励反应较大的例子：Some examples of workers who may respond more to incentives:工人可以调整他们工作的时间Workers who can adjust the number of hours they work家庭有第二个赚钱的人Families with second earners老年人可以选择何时退休Elderly who can choose when to retire考虑从事地下经济Workers in the underground economy27无谓损失和税收收入随税收变动而变动Deadweight Loss and Tax Revenueas Taxes Vary无谓损失和税收收入都随税率增加而增加，税收无谓损失的增加要快于税收规模With each increase in the taxrate, the deadweight loss of thetax rises even more rapidly thanthe size of the tax.2829无谓损失和税收收入Deadweight Loss and Tax Revenue...P B QuantityQ 20PriceQ 1DemandSupply税收收入Tax revenueP S 无谓损失Deadweight loss(a)小额税Small Tax30DemandSupply税收收入Taxrevenue P B QuantityQ 20PriceQ 1P S无谓损失Deadweightloss无谓损失和税收收入Deadweight Loss and Tax Revenue...(b) 中额税Medium Tax31Ta xrevenu eP B QuantityQ 20PriceQ 1DemandSupply P S无谓损失Deadweight loss无谓损失和税收收入Deadweight Loss and Tax Revenue...(c) 大额税Large Tax无谓损失和税收收入Deadweight Loss and Tax Revenue 当小额税时，税收收入小For the small tax, tax revenue is small.当税收规模增加时，税收收入增加As the size of the tax rises, tax revenuegrows.但是当税收规模继续增加时，税收收入减少，因为高税率减小市场的规模But as the size of the tax continues to rise,tax revenue falls because the higher taxreduces the size of the market.32无谓损失和税收收入随税收变动而变动Deadweight Loss and Tax Revenue Vary with the Size of the Tax...(a) 无谓损失Deadweight Loss无谓损失DeadweightLoss0税收规模Tax Size3334无谓损失和税收收入随税收变动而变动Deadweight Loss and Tax Revenue Vary with the Size of the Tax...(b) 收入Revenue(Laffer 曲线the Laffer curve)税收收入Tax Revenue 0税收规模Tax Size无谓损失和税收收入随税收变动而变动Deadweight Loss and Tax Revenue Vary with the Size of the Tax随着税收规模提高，税收的无谓损失迅速扩大As the size of a tax increases, its deadweightloss quickly gets larger.与此相比，随着税收规模提高，税收收入先增加，然后随着税收规模越来越大，市场收缩非常之大，以至于税收收入开始减小By contrast, tax revenue first rises with the size of a tax; but then, as the tax gets larger, themarket shrinks so much that tax revenue starts to fall.35Laffer曲线和供应学派经济学The Laffer Curve andSupply-Side EconomicsLaffer曲线描述了税率和税收收入之间的关系The Laffer curve depicts the relationship between tax rates and tax revenue.供应学派经济学指的是里根和Laffer的观点，他们建议减税会鼓励更多的人工作，由此有潜力增加税收Supply-side economics refers to the views of Reagan and Laffer who proposed that a tax cut would induce more people to work and thereby have the potential to increase tax revenues.36总结Summary一种物品的税收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A tax on a good reduces the welfare of buyers and sellers of the good. And the reduction in consumer and producer surplus usually exceeds the revenues raised by the government.37总结Summary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The fall in total surplus –the sum of consumer surplus, producer surplus, and tax revenue –is called the deadweight loss of the tax.38总结Summary税收有无所损失是因为它引起买者少消费和卖者少生产Taxes have a deadweight loss because they cause buyers to consume less and sellers to produce less.这一行为的变动使市场规模缩小到使总剩余最大化的水平之下This change in behavior shrinks the size of the market below the level that maximizes total surplus.39总结Summary税收增加越多，它对激励的扭曲越大，而且，无谓损失增加也越大As a tax grows larger, it distorts incentives more, and its deadweight loss grows larger.税收收入起初随税收规模扩大而增加Tax revenue first rises with the size of a tax.但是，最终由于高税收减少市场规模，也就减少了税收收入Eventually, however, a larger tax reduces tax revenue because it reduces the size of the market.40。