曼昆经济学原理Chap08.ppt

,税收的成本,Chapter 8 第八章,Copyright 2001 by Harcourt, Inc. All rights reserved. Requests for permission to make copies of any part of the work should be mailed to: Permissions Department, Harcourt College Publishers, 6277 Sea Harbor Drive, Orlando, Florida 32887-6777.,税收成本 The Costs of Taxation,税收怎样影响了市场参与者的经济福利？,税收的成本 The Costs of Taxation,对商品征税，无论是向消费者还是生产者征税，结果是一样的，买者支付的价格上升，卖方得到的价格下降。,征税的结果,Price,0,Quantity,Supply,Demand,The Effects of a Tax 税收的影响,A tax places a wedge between the price buyers pay and the price sellers receive. Because of this tax wedge, the quantity sold falls below the level that would be sold without a tax. The size of the market for that good shrinks.,Tax Revenue税收,T = the size of the tax 税收规模,Q = the quantity of the good sold 销售量,TQ = 政府税收,Tax Revenue.税收,Price,0,Quantity,Quantity without tax 无税时的数量,Supply,Demand,卖方得到价Price sellers receive,Quantity with tax 有税时的数量,卖方支付价Price buyers pay,税收怎样影响经济福利.请同学们比较有税和无税时的经济福利,Quantity,0,Price,Demand,Supply,Q1,Q2,税收减少了消费者剩余 (B+C) 以及生产者剩余 (D+E),税收 = (B+D),无谓损失s = (C+E),征税时的福利变化,Without Tax,With Tax,Change,Consumer Surplus,A + B + C,A,- (B + C),Producer Surplus,D + E + F,F,- (D + E),Tax Revenue,none,B + D,+ (B + D),Total Surplus,A + B + C + D + E + F,A + B + D + F,- (C + E ),The area C+E shows the fall in total surplus and is the deadweight loss of the tax.,How a Tax Affects Welfare 税收怎样影响福利,The change in total welfare includes:总福利的变化包括： The change in consumer surplus, The change in producer surplus, The change in tax revenue. The losses to buyers and sellers exceed the revenue raised by the government.买卖双方的损失超过了政府得到的收入 This fall in total surplus is called the deadweight loss.经济总剩余（总福利）的减少叫做无谓损失,Deadweight Losses and the Gains from Trade 无谓损失与贸易的好处,Taxes cause deadweight losses because they prevent buyers and sellers from realizing some of the gains from trade. 税收引起无谓损失，因为它使买卖双方损失（不能实现）了一部分贸易的好处,The Deadweight Loss.,Quantity,0,Price,Demand,Supply,Q1,PB,无税时的价格 Price = P1 without tax,PS,Q2,Determinants of Deadweight Loss无谓损失的决定因素,What determines whether the deadweight loss from a tax is large or small?什么因素决定了税收引起的无谓损失是大还是小呢？ The magnitude of the deadweight loss depends on how much the quantity supplied and quantity demanded respond to changes in the price. That, in turn, depends on the price elasticities of supply and demand.它依赖于供给和需求的价格弹性,Tax Distortions and Elasticities. 税收扭曲与弹性,Quantity,Price,Demand,Supply,0,(a) 缺乏弹性的供给Inelastic Supply,Tax Distortions and Elasticities.,Quantity,Price,Demand,Supply,0,(b) 富有弹性的供给 Elastic Supply,Tax Distortions and Elasticities.,Quantity,Price,Demand,Supply,0,(c) 缺乏弹性的需求Inelastic Demand,Tax Distortions and Elasticities.,Quantity,Price,Demand,Supply,0,(d) 有弹性的需求 Elastic Demand,请坐在最后一排的同学回答问题,如果供给和需求对价格变化都缺乏弹性，无谓损失大还是小？ 如果供给和需求对价格变化都弹性很大，无谓损失大还是小？,Determinants of Deadweight Loss无谓损失的决定因素,The greater the elasticities of demand and supply:供求弹性越大 the larger will be the decline in equilibrium quantity and,均衡数量减少越多 the greater the deadweight loss of a tax. 无谓损失越多,The Deadweight Loss Debate 关于无谓损失的争论,Some economists argue that labor taxes are highly distorting and believe that labor supply is more elastic.一些经济学家认为劳动税是严重扭曲的，他们相信劳动供给是更富有弹性的。,The Deadweight Loss Debate,Some examples of workers who may respond more to incentives: Workers who can adjust the number of hours they work Families with second earners Elderly who can choose when to retire Workers in the underground economy (i.e. those engaging in illegal activity),无谓损失和税收随着税率变化Deadweight Loss and Tax Revenue as Taxes Vary,随着税率的提高，税收引起的无谓损失比税收的增长更快。 With each increase in the tax rate, the deadweight loss of the tax rises even more rapidly than the size of the tax.,Deadweight Loss and Tax Revenue.,PB,Quantity,Q2,0,Price,Q1,Demand,Supply,PS,(a) Small Tax,Demand,Supply,PB,Quantity,Q2,0,Price,Q1,PS,Deadweight Loss and Tax Revenue.,(b) Medium Tax,PB,Quantity,Q2,0,Price,Q1,Demand,Supply,PS,Deadweight Loss and Tax Revenue.,(c) Large Tax,Deadweight Loss and Tax Revenue,For the small tax, tax revenue is small. As the size of the tax rises, tax revenue grows. But as the size of the tax continues to rise, tax revenue falls because the higher tax reduces the size of the market.,Deadweight Loss and Tax Revenue Vary with the Size of the Tax.,(a) Deadweight Loss,Deadweight Loss,0,Tax Size,Deadweight Loss and Tax Revenue Vary with the Size of the Tax.,(b) Revenue (the Laffer curve) 拉弗曲线,Tax Revenue,0,Tax Size,Deadweight Loss and Tax Revenue Vary with the Size of the Tax,As the size of a tax increases, its deadweight loss quickly gets larger. 随着税收规模（税率）提高，无谓损失迅速增大 By contrast, tax revenue first rises with the size of a tax; but then, as the tax gets larger, the market shrinks so much that tax revenue starts to fall. 比较可知，随着税收规模提高，一开始税收增加；但税收规模更大以后，市场过度萎缩，税收开始下降。,The Laffer Curve and Supply-Side Economics,The Laffer curve depicts the relationship between tax rates and tax revenue. 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.,Summary,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.,Summary,The fall in total surplus the sum of consumer surplus, producer surplus, and tax revenue is called the deadweight loss of the tax.,Summary,Taxes have a deadweight loss because they cause buyers to consume less and sellers to produce less. This change in behavior shrinks the size of the market below the level that maximizes total surplus.,Summary,As a tax grows larger, it distorts incentives more, and its deadweight loss grows larger. Tax revenue first rises with the size of a tax. Eventually, however, a larger tax reduces tax revenue because it reduces the size of the market.,The Effects of a Tax.,Price,0,Quantity,Supply,Demand,Tax Revenue.,Price,0,Quantity,Quantity without tax,Supply,Demand,Price sellers receive,Quantity with tax,Price buyers pay,How a Tax Affects Welfare.,Quantity,0,Price,Demand,Supply,Q1,Q2,Tax reduces consumer surplus by (B+C) and producer surplus by (D+E),Tax revenue = (B+D),Deadweight Loss = (C+E),The Deadweight Loss.,Quantity,0,Price,Demand,Supply,Q1,PB,Price = P1 without tax,PS,Q2,Tax Distortions and Elasticities.,Quantity,Price,Demand,Supply,0,(a) Inelastic Supply,Tax Distortions and Elasticities.,Quantit