Chapter8 The Instruments of Trade
Policy








Introduction导论
Basic Tariff Analysis基本的关税分析
Costs and Benefits of a Tariff关税成本与收益
Other Instruments of Trade Policy其他贸易政策工具
The Effects of Trade Policy: A Summary贸易政策效应
Summary总结
Appendix I: Tariff Analysis in General Equilibrium附录1
Appendix II: Tariffs and Import Quotas in the Presence of
Monopoly附录2
1
Introduction

This chapter is focused on the following questions:本章研究
的中心问题
 What are the effects of various trade policy instruments?
不同贸易政策工具的效应
Who will benefit and who will lose from these trade
policy instruments?不同政策工具下谁受益，谁受损？
 What are the costs and benefits of protection?
保护的成本与收益Will the benefits outweigh the costs?
收益是否大于成本
 What should a nation’s trade policy be?一国贸易政策是怎
样的？
For example, should the United States use a tariff or
an import quota to protect its automobile industry
against competition from Japan and South Korea?例如
美国对日本和韩国进口汽车的政策：关税还是补贴。
2
Classification of Commercial Policy Instruments
政策工具分类
Commercial Policy Instruments
Trade Contraction
Price
Quantity
Tariff
Export tax
Import quota
Voluntary
Export
Restraint
(VER)
Trade Expansion
Price
Import subsidy
Export subsidy
Quantity
Voluntary
Import
Expansion
(VIE)
3
8-1 Basic Tariff Analysis关税基本分
析

Tariffs can be classified as:关税分类
 Specific tariffs(从量关税)
 Taxes that are levied as a fixed charge for each unit of
goods imported对每单位进口商品征收固定的税额
 Example: A specific tariff of $10 on each imported bicycle with
an international price of $100 means that customs officials
collect the fixed sum of $10.如：对每辆进口的自行车征收10元
关税
 Ad valorem tariffs(从价关税)
 Taxes that are levied as a fraction of the value of the
imported goods对进口商品价值征收一定比例的关税。
 Example: A 20% ad valorem tariff on bicycles generates a $20
payment on each $100 imported bicycle.对每进口100元征收
20%的关税。
4
A compound duty (tariff) is a combination of an ad
valorem and a specific tariff.
Select tariff
Modern governments usually prefer to protect
domestic industries through a variety of nontariff
barriers, such as:非关税壁垒
Import quotas进口配额
Limit the quantity of imports进口数量的限制
Export restraints(P186)出口限制
Limit the quantity of exports出口数量限制
5
 Supply,
Demand, and Trade in a Single
Industry供给、需求以及单一行业内贸易
 Suppose that there are two countries (Home and Foreign).两个国家
 Both countries consume and produce wheat, which can be costless
transported between the countries.两者均生产和消费小麦，无运输成
本
 In each country, wheat is a competitive industry.小麦是竞争行业
 Suppose that in the absence of trade the price of wheat at Home
exceeds the corresponding price at Foreign.在无贸易情况下，本国小
麦价格高于外国小麦的价格
 This implies that shippers begin to move wheat from Foreign to
Home. 意味着小麦将从外国运往本国。
The export of wheat raises its price in Foreign and lowers its
price in Home until the initial difference in prices has been
eliminated.出口使外国小麦价格上升，本国小麦价格降低
6
determine the world price (Pw，世界价格)
and the quantity trade (Qw，贸易量), two
curves are defined:
 To
Home import demand curve进口需求曲线
Shows the maximum quantity of imports the Home
country would like to consume at each price of the
imported good.本国消费者的需求量超过本国生产者
供给量的部分
That is, the excess of what Home consumers demand over
what Home producers supply: MD = D(P) – S(P)
Foreign export supply curve出口供给曲线
Shows the maximum quantity of exports Foreign
would like to provide the rest of the world at each
price生产者供给量超过本国消费者需求的部分.
That is, the excess of what Foreign producers supply over
what foreign consumers demand: XS = S*(P*) – D*(P*)
7
Figure 8-1: Deriving Home’s Import Demand Curve(进口需求曲线)
S
Price, P
Price, P
A
PA
2
P2
1
P1
MD
D
S1 S2
D2 D1 Quantity, Q
D2 – S2
D1 – S1
Quantity, Q
8
 Properties
of the import demand curve
进口需求曲线的特征:
It intersects the vertical axis at the closed
economy price of the importing country.和纵
坐标相交于不存在贸易时的价格点。
It is downward sloping.向下倾斜
It is flatter than the domestic demand curve
in the importing country.比国内需求曲线更平
坦
9
Figure 8-2: Deriving Foreign’s Export Supply Curve外国出口供给曲线
Price, P
S*
Price, P
XS
P2
P1
P*A
D*
D*2 D*1
S*1 S*2 Quantity, Q
S*1 – D*1 S*2 – D*2 Quantity, Q
10
 Properties
of the export supply curve出
口供给曲线的特征:
It intersects the vertical axis at the closed
economy price of the exporting country.交纵
坐标于封闭经济时价格水平
It is upward sloping.向上倾斜
It is flatter that the domestic supply curve in
the exporting country.比国内供给曲线更平坦
11
Figure 8-3: World Equilibrium(世界均衡）
Price, P
XS
1
PW
MD
QW
Quantity, Q
12

Useful definitions:定义
 The terms of trade is the relative price of the exportable good
expressed in units of the importable good.贸易条件
 A small country is a country that cannot affect its terms of trade
no matter how much it trades with the rest of the world.小国：不
管其是否与其他国家进行贸易，该国不能影响到贸易条件的变化。
（无法影响外国出口商品的）

The analytical framework will be based on either of the
following: 分析框架将基于以下两点：
 Two large countries trading with each other两大国相互贸易
 A small country trading with the rest of the world小国与其他国家
交易
13

Effects of a Tariff（关税的影响）
 Assume that two large countries trade with each other.
假定两大国相互贸易
 Suppose Home imposes a tax of $2 on every bushel
of wheat imported. 假定本国对每单位进口小麦征收2
美元关税
 Then shippers will be unwilling to move the wheat unless the
price difference between the two markets is at least $2.出口
商只有在两国小麦价格差在2美元时，才愿意出口小麦。
 Figure 8-4 illustrates the effects of a specific tariff of
$t per unit of wheat.图例说明
14
Figure 8-4: Effects of a Tariff关税的影响分析
Home market本国
Price, P
World market世界
Price, P
Price, P
S
PT
PW
Foreign market外国
S*
XS
2
t
P *T
1
3
MD
D*
D
Quantity, Q
QT QW
Quantity, Q
Quantity, Q
15
In the absence of tariff, the world price of wheat
(Pw) would be equalized in both countries.在不存
在关税时，世界价格将与两国价格相等
With the tariff in place, the price of wheat rises to
PT at Home and falls to P*T (= PT – t) at Foreign
until the price difference is $t.存在关税时，本国价
格提高，外国价格减少，其差额为关税t
In Foreign: producers supply less and consumers
demand more due to the lower price, so that fewer
exports are supplied.在外国，生产者将减少供应，消费
需求增加，更少的出口量
Thus, the volume of wheat traded declines due to the
imposition of the tariff.由于进口关税的存在，小麦的贸
易量将减少。
In Home: producers supply more and consumers
demand less due to the higher price, so that fewer
imports are demanded.在本国，供应量增加，消费需求16
减少，进口减少。
The increase in the domestic Home price
is less than the tariff, because part of the
tariff is reflected in a decline in Foreign’ s
export price. 国内价格上升的幅度小于关税，
因为有一部分关税反映在外国价格的降低上。
If Home is a small country and imposes a tariff,
the foreign export prices are unaffected and the
domestic price at Home (the importing country)
rises by the full amount of the tariff.如果本国是
小国，并征收关税，外国出口价格不受影响，本
国征收关税全部反映在本国价格上升上。
17
Figure 8-5: A Tariff in a Small Country小国关税
Price, P
S
PW + t
PW
D
S1 S2
D2 D1
Quantity, Q
Imports after tariff
Imports before tariff
18
 Measuring
the Amount of Protection衡
量保护程度
In analyzing trade policy in practice, it is
important to know how much protection a
trade policy actually provides.保护的程度
One can express the amount of protection as a
percentage of the price that would prevail under
free trade.一个简单的表达为：与自由贸易相比，
价格提高了多少 个百分比。
Two problems arise from this method of
measurement:这一方法衡量的两个问题
 In the large country case, the tariff will lower the
foreign export price.在大国情况下，关税将降低
外国出口价格，而不是完全反映在本国价格的提
高上。
 Tariffs may have different effects on different
stages of production of a good.关税对不同生产阶
19

Effective rate of protection 有效保护率
 One must consider both the effects of tariffs on the
final price of a good, and the effects of tariffs on the
costs of inputs used in production.必须同时考虑关税
对中间产品和最终产品的保护
 The actual protection provided by a tariff will not equal the
tariff rate if imported intermediate goods are used in the
production of the protected good.如果进口中间品被投入到保
护产品的生产中，则关税实际保护率不等于关税率。
 例Example: A European airplane that sells for $50 million has
cost $60 million to produce. Half of the purchase price of the
aircraft represents the cost of components purchased from
other countries. A subsidy of $10 million from the European
government cuts the cost of the value added to purchasers of
the airplane from $30 to $20 million. Thus, the effective rate of
protection is (30-20)/20 = 50%.
20
ERR有效保护率
 有效保护率（Effective
Rate of Protection，
简称ERP），是指关税对国内增加值（从而
对国内就业）的保护程度。有效保护率是用
征收进口关税后国内增加值的增加程度来度
量的。如果某种商品征收关税前的国内增加
值为V，征收关税后国内增加值为，
V  ， 则有
效保护率为
V  V
ERP 
V
21
美国、日本和欧共体的名义关税税率和实际关
税税率
欧共体
日本
美国
名义税 有效
率
税率
名义税 有效
率
税率
名义 有效
税率 税率
牛奶、奶
酪和黄油
可可产品
和巧克力
棉籽油
22
59.9
37.3
248.8 10.8 36.9
12.8
34.6
22.8
80.7
11
79
25.8
200.3 59.6 465.9
豆油
11
148.1 25.4
286.3 22.5 252.9
烟草和香
烟
87.1
147.3 339.5
405.6 68
4.2
16.2
113.2
22
Exercise(p191)
Suppose that an automobile sells on the world market
for $8000.The parts out of which that automobile is
made sell for $6000.Country A wants to develop an auto
assembly industry. Country B wants to develop a parts
industry which already has an assembly industry.
①Country A places a 25 percent tariff on imported
autos.（in order to encourage a domestic auto industry)
②Country B imposes a 10 percent tariff on imported
parts.（in order to encourage domestic production of
parts)
23
8-2 Costs and Benefits of a Tariff
关税的成本和收益



A tariff raises the price of a good in the importing country and
lowers it in the exporting country.关税提高了商品在进口国的
价格，降低了在出口国家的价格。
As a result of these price changes:(价格变化的结果)
 Consumers lose in the importing country and gain in the
exporting country进口国消费者福利损失，而出口国消费
者受益。
 Producers gain in the importing country and lose in the
exporting country进口国生产者获益，而出口国受损。
 Government imposing the tariff gains revenue政府受益
To measure and compare these costs and benefits, we need
to define consumer and producer surplus.为了比较关税的成
本和收益，先定义消费者剩余和生产者剩余。
24

Consumer and Producer Surplus消费者和生产者
剩余
 Consumer surplus(消费者剩余)
 It measures the amount a consumer gains from a purchase by
the difference between the price he actually pays and the price
he would have been willing to pay.是衡量消费者在一次购买中
他愿意支付的价格与他实际支付价格之间的差额。
 It can be derived from the market demand curve.可以从市场需
求曲线来推导。
 Graphically, it is equal to the area under the demand curve and
above the price.等于需求曲线和价格之间的差额。
 Example: Suppose a person is willing to pay $20 per packet of
pills, but the price is only $5. Then, the consumer surplus
gained by the purchase of a packet of pills is $15.
25
Figure 8-6: Deriving Consumer Surplus from the Demand Curve
从需求曲线推导消费者剩余
Price价格, P
$12
$10
$9
D
8 9 10 11
Quantity,数量 Q
Figure 8-7:Geometry of Consumer Surplus(消费者剩余的几何图形)
Price, P
a
P1
P2
b
D
Q1 Q2
Quantity, Q
27
Producer surplus生产者剩余
It measures the amount a producer gains from a
sale by the difference between the price he
actually receives and the price at which he would
have been willing to sell.
It can be derived from the market supply curve.
Graphically, it is equal to the area above the supply
curve and below the price.
Example: A producer willing to sell a good for $2
but receiving a price of $5 gains a producer
surplus of $3.
28
Figure 8-8: Geometry of Producer Surplus
Price, P
S
P2
d
P1
c
Q1
Q2
Quantity, Q
29
 Measuring
the Cost and Benefits
Is it possible to add consumer and producer
surplus?
We can (algebraically) add consumer and producer
surplus because any change in price affects each
individual in two ways:
As a consumer
As a worker
We assume that at the margin a dollar’s worth of
gain or loss to each group is of the same social worth.
30
Figure 8-9: Costs and Benefits of a Tariff for the Importing
Country(P195)
Price, P
S
= consumer loss (a + b + c + d)
= producer gain (a)
= government revenue gain (c + e)
PT
PW
a
b
c
d
e
P*T
D
S1 S2
D2 D1
QT
Quantity, Q
The areas of the two triangles b and d measure
the loss to the nation as a whole (efficiency loss)
and the area of the rectangle e measures an
offsetting gain (terms of trade gain).
The efficiency loss arises because a tariff distorts
incentives to consume and produce.
Producers and consumers act as if imports were more
expensive than they actually are.
Triangle b is the production distortion loss and triangle d
is the consumption distortion loss.
The terms of trade gain arises because a tariff
lowers foreign export prices.
32
If the terms of trade gain is greater than the
efficiency loss, the tariff increases welfare for
the importing country.
In the case of a small country, the tariff reduces
welfare for the importing country.
33
Figure 8-10: Net Welfare Effects of a Tariff(P197)
Price, P
S
= efficiency loss (b + d)
= terms of trade gain (e)
PT
PW
P*T
d
b
e
D
Quantity, Q
Imports
美国某些进口商品关税的经济效应
产品
关税％ 消费者成 关税收入 生产者 载重成本 每一工作的消
本（百万
美元）
（百万美 收益
元）
（千美
元）
（百万美 费者成本（千
元）
美元）
橡胶鞋
41.9
272.2
188.4
44.1
37.9
113
女鞋
10
325.1
253.4
54.6
17.1
93
瓷砖
19.1
90
77.6
10
2.5
225
箱包
16.3
186.3
39.8
36.4
10.2
104
皮手套
15.3
28.1
15
10.8
2.3
47
瓷器
14.2
43.8
33.3
9.2
1.4
73
假珠宝
9.9
86.7
59.5
20.7
6.7
87
玻璃器
皿
12.9
185.8
99
7.2
9.6
74
自行车
11
38.1
26.4
10
1.8
64
35
8-3 Other Instruments of Trade
Policy
Figure 8-11: Effects of an Export Subsidy(p198)
Price, P
S
PS
Subsidy P
W
P*S
a
c
b
e
d
f
g
= producer gain
(a + b + c)
= consumer loss (a + b)
= cost of
government subsidy
(b + c + d + e + f + g)
D
Quantity, Q
Exports
 Export
Subsidies: Theory
Export subsidy
A payment by the government to a firm or
individual that ships a good abroad(p197)
When the government offers an export subsidy, shippers
will export the good up to the point where the domestic
price exceeds the foreign price by the amount of the
subsidy.
It can be either specific or ad valorem.
37
An export subsidy raises prices in the
exporting country while lowering them in the
importing country.
In addition, and in contrast to a tariff, the
export subsidy worsens the terms of trade.
An export subsidy unambiguously leads to
costs that exceed its benefits. (P197)
38
Figure 8-12: Europe’s Common Agricultural Program(p199)
Price, P
S
Support price
EU
price
without
imports
= cost of government
subsidy
World price
D
Quantity, Q
Exports

Import Quotas: Theory
 An import quota is a direct restriction on the quantity
of a good that is imported. (P200)
 Example: The United States has a quota on imports of
foreign cheese.
 The restriction is usually enforced by issuing licenses
to some group of individuals or firms.
 Example: The only firms allowed to import cheese are certain
trading companies.
 In some cases (e.g. sugar and apparel), the right to
sell in the United States is given directly to the
governments of exporting countries.
40
An import quota always raises the domestic
price of the imported good.
License holders are able to buy imports and
resell them at a higher price in the domestic
market.
The profits received by the holders of import
licenses are known as quota rents.(P200)
41
Welfare analysis of import quotas versus of
that of tariffs
The difference between a quota and a tariff is
that with a quota the government receives no
revenue.
In assessing the costs and benefits of an import
quota, it is crucial to determine who gets the
rents.
When the rights to sell in the domestic market are
assigned to governments of exporting countries, the
transfer of rents abroad makes the costs of a quota
substantially higher than the equivalent tariff.
42
Figure 8-13: Effects of the U.S. Import Quota on Sugar(P201)
Price, $/ton
Supply
= consumer loss
(a + b + c + d)
= producer gain (a)
Price in U.S. Market 466
World Price 280
a
b
c
d
= quota rents (c)
Demand
5.14 6.32 8.45 9.26
Import quota:
2.13 million tons
Quantity of sugar,
million tons
 Voluntary
Export Restraints
A voluntary export restraint (VER) is an
export quota administered by the exporting
country.(P202)
It is also known as a voluntary restraint agreement
(VRA).
VERs are imposed at the request of the
importer and are agreed to by the exporter to
forestall other trade restrictions.
44
 A VER is exactly like an import quota where the licenses are
assigned to foreign governments and is therefore very costly to
the importing country.
 A VER is always more costly to the importing country than a tariff
that limits imports by the same amount.
 The tariff equivalent revenue becomes rents earned by
foreigners under the VER.
Example: About 2/3 of the cost to consumers of the three
major U.S. voluntary restraints in textiles and apparel,
steel, and automobiles is accounted for by the rents
earned by foreigners.
 A VER produces a loss for the importing country.
45
 Local
Content Requirements
A local content requirement is a regulation
that requires that some specified fraction of a
final good be produced domestically.(p203)
This fraction can be specified in physical units or in
value terms.
Local content laws have been widely used by
developing countries trying to shift their
manufacturing base from assembly back into
intermediate goods.
46
 Local content laws do not produce either government
revenue or quota rents.
 Instead, the difference between the prices of imports and
domestic goods gets averaged in the final price and is passed
on to consumers.
 Example: Suppose that auto assembly firms are required to use
50% domestic parts. The cost of imported parts is $6000 and the
cost of the same parts domestically is $10,000. Then the average
cost of parts is $8000 (0.5 x $6000 + 0.5 x $10,000).
 Firms are allowed to satisfy their local content
requirement by exporting instead of using parts
domestically.
47

Other Trade Policy Instruments
 Export credit subsidies
 A form of a subsidized loan to the buyer of exports.
 They have the same effect as regular export subsidies.
 National procurement
 Purchases by the government (or public firms) can be
directed towards domestic goods, even if they are more
expensive than imports.
 Red-tape barriers
 Sometimes governments place substantial barriers
based on health, safety and customs procedures.
48
政府财政总支出占国内生产总值的比重
国家
美国
日本
德国
法国
英国
瑞典
欧共体
1985
33.8
29.4
43.4
49.8
42.9
60.4
47.2
1990
33.6
30.5
44.2
47.5
39
55.9
45.9
1995
32.9
34.4
46.3
51.4
42.2
61.9
47.8
2001
31.2
36.7
45.7
48.8
38.3
52.2
44.5
49
8-4 The Effects of Trade Policy:
A Summary
Table 8-1: Effects of Alternative Trade Policies(P206)
50
Summary


A tariff drives a wedge between foreign and domestic
prices, raising the domestic price but by less than the
tariff rate (except in the “small” country case).
 In the small country case, a tariff is fully reflected in
domestic prices.
The costs and benefits of a tariff or other trade policy
instruments may be measured using the concepts of
consumer and producer surplus.
 The domestic producers of a good gain
 The domestic consumers lose
 The government collects tariff revenue
51
Summary



The net welfare effect of a tariff can be separated into
two parts:
 Efficiency (consumption and production) loss
 Terms of trade gain (is zero in the case of a small
country)
An export subsidy causes efficiency losses similar to a
tariff but compounds these losses by causing a
deterioration of the terms of trade.
Under import quotas and voluntary export restraints the
government of the importing country receives no
revenue.
52
Appendix I: Tariff Analysis in
General Equilibrium(P211)
Table 8AI-1: Free Trade Equilibrium for a Small Country
Food production and
consumption, QF, DF
D1
Q1
Slope = - P*M/P*F
Manufactures production and
consumption, QM, DM
Appendix I: Tariff Analysis in
General Equilibrium
Table 8AI-2: A Tariff in a Small Country
QF, DF
D2
D1
Slope = - P*M/P*F (1 + t)
Q2
Q1
QM, DM
Appendix I: Tariff Analysis in
General Equilibrium
Table 8AI-3: Effect of a Tariff on the Terms of Trade
Home imports of food, DF - QF
Foreign exports of food, Q*F - D*F
Slope = (P*M/P*F)2
M2
M1
Slope = (P*M/P*F)1
1
F
3
2
O
Home exports of manufactures, QM - DM
Foreign imports of manufactures, D*M - Q*M
Appendix II: Tariffs and Import
Quotas in the Presence of Monopoly
Table 8AII-1: A Monopolist Under Free Trade
Price, P
MC
PM
PW
D
MR
Qf QM
Df
Quality, Q
Appendix II: Tariffs and Import
Quotas in the Presence of Monopoly
Table 8AII-2: A Monopolist Protected by a Tariff
Price, P
MC
PM
PW + t
PW
D
MR
Qf QtQM
Dt
Df
Quality, Q
Appendix II: Tariffs and Import
Quotas in the Presence of Monopoly
Table 8AII-3: A Monopolist Protected by an Import Quota
Price, P
MC
Pq
PW
Dq
D
MRq
Qq
Quality, Q
Appendix II: Tariffs and Import
Quotas in the Presence of Monopoly
Table 8AII-4: Comparing a Tariff and a Quota
Price, P
MC
Pq
PW + t
PW
Dq
D
MRq
Qq
Qt
Quality, Q
Reading
孙烽（2000）：关税、技术创新与经济增长，世
界经济文汇，第1期
 耿伟（2003）：关于贸易保护政策选择的理论分
析，中央财经大学学报，第7期

60
Problem
 P207,3
61