第八章应用：税收的代价Application:
The Costs of Taxation
2
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 affect the economic well-being of market participants?
3
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 not matter whether a tax on a good is levied on buyers or sellers of the good…the price paid by buyers rises, and the price received by sellers falls.
4
税收的影响
The Effects of a Tax...
Price
Quantity
无税收时的数量
Quantity without tax Supply
Demand
没有税收时的价格Price without 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Price sellers receive
5
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.
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税收收入Tax Revenue
T = 税收规模the size of the tax Q = 销售量the quantity of the good sold
T ×Q = 税收收入the government’s tax revenue
7
税收收入
Tax Revenue...
Price
Quantity
Quantity without tax
Supply
Demand
Price sellers
receive
Quantity with tax 税收规模Size of tax (T)
销售数量Quantity sold (Q)
税收收入Tax Revenue (T x Q)
Price buyers
pay
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税收如何影响福利
How a Tax Affects Welfare...
Quantity 0
Price
Demand
Supply
Q 1
A
B C F
D 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) and producer surplus by (D+E)
税收收入Tax revenue = (B+D)
无谓损失
Deadweight Loss = (C+E)
Price buyers pay =P B P 1
Price without tax
=P S Price sellers receive
=9
税收导致的福利变化
Changes in Welfare
from 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 is
the deadweight loss of the tax.10
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的税收收入
The losses to buyers and sellers exceed the revenue raised 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 distortion 11
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.
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无谓损失
The Deadweight Loss...
Quantity
Price
Demand
Supply
Q 1
P B
没有税收时的价格
Price = P 1without tax
P S
Q 2税收规模Size of tax
损失的贸易好处Lost gains from 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 in quantity due to the tax
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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 from a 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 quantity demanded 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 of supply and demand.
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税收扭曲和弹性
Tax Distortions and Elasticities
Quantity
Price
Demand
Supply
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 loss of a tax is small.
(a) 缺乏弹性的供给Inelastic Supply 税收规模Size of tax
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税收扭曲和弹性
Tax Distortions and Elasticities
Quantity
Price
Demand
Supply
税收规模Size of 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Elastic Supply
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税收扭曲和弹性
Tax Distortions and Elasticities
Quantity
Price
Demand
Supply
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 tax
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税收扭曲和弹性
Tax Distortions and Elasticities
Quantity
Price
Demand
Supply
Size 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
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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.
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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.
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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 economy 21
无谓损失和税收收入随税收变动而变动
Deadweight Loss and Tax Revenue
as 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 tax rate, the deadweight loss of the tax rises even more rapidly than
the size of the tax.
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无谓损失和税收收入
Deadweight Loss and Tax Revenue...
P B Quantity
Q 20
Price
Q 1
Demand
Supply
税收收入
Tax revenue
P S
无谓损失Deadweight
loss
(a)小额税Small Tax
23
Demand
Supply
税收收入Tax revenue
P B
Quantity
Q 20
Price
Q 1
P S
无谓损失Deadweight
loss
无谓损失和税收收入
Deadweight Loss and Tax Revenue...
(b) 中额税Medium Tax
24
T a x r e v e n u e
P B
Quantity
Q 20
Price
Q 1
Demand
Supply
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
25
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 revenue grows.
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 tax reduces the size of the market.
26
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Deadweight
Loss
税收规模Tax Size
27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
税收规模Tax Size
28
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 deadweight loss 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, the market shrinks so much that tax revenue starts to fall.
29
Laffer 曲线和供应学派经济学
The Laffer Curve and Supply-Side Economics
Laffer 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.
30
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.
31
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.
32
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.
33
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.下载本文
