05. Trade Barriers for Importing Countries

Learning objectives

By the end of this chapter, you should be able to:

Explain why governments use import barriers.
Distinguish between tariffs, quotas, tariff-rate quotas, domestic subsidies, and local content requirements.
Calculate the welfare effects of a small-country tariff.
Explain why quotas can be more restrictive than tariffs.
Calculate the effective rate of protection.
Use excess demand and export supply to interpret import-market shocks.

Why this chapter matters

Import barriers are among the most common instruments of trade policy. They can protect domestic producers, raise government revenue, and support political objectives. However, they usually raise prices for consumers and reduce national welfare.

For agricultural trade, import barriers are especially important. Many countries protect food producers, regulate food imports, and use tariffs or quotas to manage sensitive farm sectors. This chapter explains the main tools and shows how to evaluate their welfare effects.

Protectionism

Protectionism refers to government policies that restrict trade in order to shield domestic producers from foreign competition.

Common arguments for protection include:

protecting jobs,
supporting infant industries,
protecting national security,
responding to foreign subsidies,
preventing dumping,
raising government revenue,
reducing import dependence.

These arguments may be politically powerful, but the welfare effects are not always favorable. A policy can help one group and hurt another group at the same time.

Main idea

Trade barriers usually redistribute income from consumers to producers and sometimes to the government. The key welfare question is whether the gains to protected groups are larger than the losses to consumers and society.

Tariffs

A tariff is a tax on a traded product. Import tariffs are more common than export tariffs.

There are three common types of tariff.

Type	Definition	Example
Specific tariff	Fixed monetary charge per unit	10 dollars per imported bicycle
Ad valorem tariff	Percentage of import value	20 percent of the value of each imported bicycle
Compound tariff	Combination of specific and ad valorem tariff	5 dollars per unit plus 10 percent of value

Tariffs raise the domestic price of imported goods. This helps domestic producers but hurts consumers.

Small-country tariff

A small country cannot affect the world price of the imported good. It takes the world price as given.

Let:

$P_w$ be the world price,
$t$ be the tariff per unit,
$P_d$ be the domestic price after the tariff.

For a small country:

\[ P_d = P_w + t \]

The tariff raises the domestic price from $P_w$ to $P_d$.

Welfare effects of a small-country tariff

When the tariff raises the domestic price:

consumers lose because they pay a higher price and buy less,
domestic producers gain because they sell more at a higher price,
the government gains tariff revenue,
society loses because of production and consumption distortions.

The national welfare effect is:

\[ \Delta W = \Delta CS + \Delta PS + \Delta GR \]

where:

$CS$ is consumer surplus,
$PS$ is producer surplus,
$GR$ is government revenue.

For a small country, the tariff creates a deadweight loss. This has two parts:

Production loss: inefficient domestic production replaces cheaper imports.
Consumption loss: some consumers stop buying because the price is higher.

Key result

For a small importing country, a tariff reduces national welfare because the government revenue and producer gain are smaller than the consumer loss.

Worked example: a small-country tariff

Suppose the domestic market has:

\[ Q_d = 100 - 2P \]

\[ Q_s = 2P \]

The world price is:

\[ P_w = 20 \]

The government imposes a tariff:

\[ t = 5 \]

So the domestic price becomes:

\[ P_d = 25 \]

Before the tariff:

\[ Q_d = 100 - 2(20) = 60 \]

\[ Q_s = 2(20) = 40 \]

Imports are:

\[ M = 60 - 40 = 20 \]

After the tariff:

\[ Q_d = 100 - 2(25) = 50 \]

\[ Q_s = 2(25) = 50 \]

Imports are:

\[ M = 50 - 50 = 0 \]

In this example, the tariff is high enough to eliminate imports.

Python application: tariff welfare calculator

Code

import pandas as pd

# Demand and supply functions:
# Qd = a - bP
# Qs = c + dP

a = 100
b = 2
c = 0
d = 2

Pw = 20
t = 5
Pd = Pw + t

# Demand and supply quantities
Qd_free = a - b * Pw
Qs_free = c + d * Pw
M_free = Qd_free - Qs_free

Qd_tariff = a - b * Pd
Qs_tariff = c + d * Pd
M_tariff = max(Qd_tariff - Qs_tariff, 0)

# Choke price and supply intercept
P_max = a / b
P_min = -c / d if d != 0 else 0

# Surplus calculations
CS_free = 0.5 * (P_max - Pw) * Qd_free
PS_free = 0.5 * (Pw - P_min) * Qs_free
GR_free = 0
TS_free = CS_free + PS_free + GR_free

CS_tariff = 0.5 * (P_max - Pd) * Qd_tariff
PS_tariff = 0.5 * (Pd - P_min) * Qs_tariff
GR_tariff = t * M_tariff
TS_tariff = CS_tariff + PS_tariff + GR_tariff

summary = pd.DataFrame({
    "Scenario": ["Free trade", "With tariff"],
    "Price": [Pw, Pd],
    "Qd": [Qd_free, Qd_tariff],
    "Qs": [Qs_free, Qs_tariff],
    "Imports": [M_free, M_tariff],
    "CS": [CS_free, CS_tariff],
    "PS": [PS_free, PS_tariff],
    "Government revenue": [GR_free, GR_tariff],
    "Total surplus": [TS_free, TS_tariff]
})

summary

	Scenario	Price	Qd	Qs	Imports	CS	PS	Government revenue	Total surplus
0	Free trade	20	60	40	20	900.0	400.0	0	1300.0
1	With tariff	25	50	50	0	625.0	625.0	0	1250.0

Code

changes = pd.DataFrame({
    "Item": ["Change in CS", "Change in PS", "Change in government revenue", "Change in total surplus"],
    "Value": [
        CS_tariff - CS_free,
        PS_tariff - PS_free,
        GR_tariff - GR_free,
        TS_tariff - TS_free
    ]
})

changes

	Item	Value
0	Change in CS	-275.0
1	Change in PS	225.0
2	Change in government revenue	0.0
3	Change in total surplus	-50.0

Visualizing the tariff effect

Code

import numpy as np
import matplotlib.pyplot as plt

P = np.linspace(0, P_max, 200)
Qd = a - b * P
Qs = c + d * P

plt.figure()
plt.plot(Qd, P, label="Demand")
plt.plot(Qs, P, label="Supply")
plt.axhline(Pw, linestyle="--", label="World price")
plt.axhline(Pd, linestyle=":", label="World price + tariff")
plt.scatter([Qd_free, Qs_free, Qd_tariff, Qs_tariff], [Pw, Pw, Pd, Pd])
plt.xlabel("Quantity")
plt.ylabel("Price")
plt.title("Small-country tariff")
plt.legend()
plt.tight_layout()
plt.show()

A tariff raises the domestic price, reduces consumption, increases domestic production, and lowers imports.

Import quotas

An import quota is a direct limit on the quantity of imports.

For example, a country may allow only 10,000 tons of wheat to be imported in a year.

A quota has effects similar to a tariff:

it raises the domestic price,
it reduces consumption,
it increases domestic production,
it reduces imports,
it creates deadweight loss.

The main difference is the treatment of the quota rent.

Quota rents

A quota creates a gap between the domestic price and the world price. The right to import becomes valuable.

The extra profit earned by import-license holders is called quota rent.

\[ \text{Quota rent} = (P_d - P_w) \times Q_{quota} \]

Who receives this rent depends on how the quota is administered.

Quota administration method	Who gets the rent?
Government auctions import licenses	Government
Government gives licenses to domestic importers	Domestic importers
Foreign exporters receive quota rights	Foreign exporters
First come, first served	Early importers

Why quotas can be more restrictive

A tariff allows imports to rise when domestic demand increases. A quota fixes the maximum quantity of imports. If demand rises, the domestic price can rise sharply under a quota.

Tariff-rate quota

A tariff-rate quota combines a quota and a tariff.

A limited quantity of imports enters at a low tariff. Imports above that quantity face a higher tariff.

This system is common in agricultural trade because many countries want to allow some market access while still protecting sensitive domestic producers.

Import quantity	Tariff rate
Within quota	Low tariff
Above quota	High tariff

Large-country tariff

A large country can affect the world price of the imported good.

When a large importing country imposes a tariff, it reduces import demand. This may lower the foreign export price. The importing country may gain from an improvement in its terms of trade.

The welfare effect of a large-country tariff is:

\[ \Delta W = \text{terms-of-trade gain} - \text{efficiency loss} \]

A large-country tariff can theoretically improve national welfare if the terms-of-trade gain is larger than the deadweight loss. However, this result is fragile because other countries may retaliate.

Policy caution

The optimal tariff argument is theoretically valid for a large country, but it is risky in practice. Retaliation can create a trade war that makes all countries worse off.

Domestic production subsidy

A domestic production subsidy is a payment to domestic producers in import-competing sectors.

It encourages domestic production without raising the consumer price directly. For this reason, a production subsidy usually creates a smaller welfare loss than an equivalent tariff or quota.

However, it is not free. The subsidy must be financed by taxpayers.

Policy	Consumer price rises?	Government budget cost?	Main beneficiary
Tariff	Yes	No, revenue increases	Producers and government
Quota	Yes	Depends on license system	Producers and license holders
Production subsidy	No	Yes	Producers

Local content requirements and standards

A local content requirement forces firms to use a minimum share of domestic inputs. It protects domestic input suppliers but raises production costs.

Government procurement policies may also favor domestic suppliers, even when imported products are cheaper.

Health, safety, and technical standards may be legitimate. However, they can become trade barriers if they are designed or applied in a protectionist way.

Effective rate of protection

The nominal tariff measures protection on the final good. The effective rate of protection measures protection on domestic value added.

This is important because producers often use imported inputs.

The effective rate of protection is:

\[ ERP = \frac{VA_d - VA_w}{VA_w} \times 100 \]

where:

$VA_d$ is domestic value added after tariffs,
$VA_w$ is value added at world prices.

Worked example: cheese, milk, and starting culture

Suppose producing 1 kg of cheese requires:

10 liters of milk,
10 grams of starting culture.

World prices are:

Item	World price
Cheese	20 dollars per kg
Milk	1 dollar per liter
Starting culture	0.5 dollars per gram

The country imposes:

Item	Tariff
Cheese	20 percent
Milk	10 percent
Starting culture	10 percent

At world prices:

\[ \text{Input cost} = 10(1) + 10(0.5) = 15 \]

\[ VA_w = 20 - 15 = 5 \]

With tariffs:

\[ \text{Cheese price} = 20(1.20) = 24 \]

\[ \text{Milk cost} = 10(1)(1.10) = 11 \]

\[ \text{Starting culture cost} = 10(0.5)(1.10) = 5.5 \]

\[ VA_d = 24 - 11 - 5.5 = 7.5 \]

So:

\[ ERP = \frac{7.5 - 5}{5} \times 100 = 50\% \]

Although the nominal tariff on cheese is 20 percent, the effective protection of domestic value added is 50 percent.

Python application: effective rate of protection

Code

import pandas as pd

cheese_price = 20
milk_liters = 10
milk_price = 1
culture_grams = 10
culture_price = 0.5

scenarios = pd.DataFrame({
    "Scenario": [
        "Initial tariffs",
        "Double cheese and milk tariffs",
        "Double all tariffs"
    ],
    "Cheese tariff": [0.20, 0.40, 0.40],
    "Milk tariff": [0.10, 0.20, 0.20],
    "Culture tariff": [0.10, 0.10, 0.20]
})

VA_world = cheese_price - (milk_liters * milk_price) - (culture_grams * culture_price)

rows = []
for _, row in scenarios.iterrows():
    output_domestic = cheese_price * (1 + row["Cheese tariff"])
    milk_domestic = milk_liters * milk_price * (1 + row["Milk tariff"])
    culture_domestic = culture_grams * culture_price * (1 + row["Culture tariff"])
    VA_domestic = output_domestic - milk_domestic - culture_domestic
    ERP = (VA_domestic - VA_world) / VA_world * 100
    rows.append({
        "Scenario": row["Scenario"],
        "World value added": VA_world,
        "Domestic value added": VA_domestic,
        "ERP percent": ERP
    })

erp_results = pd.DataFrame(rows)
erp_results

	Scenario	World value added	Domestic value added	ERP percent
0	Initial tariffs	5.0	7.5	50.0
1	Double cheese and milk tariffs	5.0	10.5	110.0
2	Double all tariffs	5.0	10.0	100.0

Interpretation

Effective protection can be much larger than nominal protection when tariffs on the final product are high and tariffs on imported inputs are low. This is why economists focus on value added, not only the tariff on the final good.

Applied example: Egypt wheat imports and an external supply shock

Food-importing countries are exposed to world market shocks. Suppose Egypt imports wheat from the rest of the world. Its domestic market is:

\[ Q_d = 20 - P \]

\[ Q_s = P - 2 \]

Egypt’s excess demand is:

\[ ED = Q_d - Q_s = 22 - 2P \]

Suppose the rest of the world export supply is initially:

\[ ES = -10 + 2P \]

The free-trade equilibrium is found by setting:

\[ ED = ES \]

Now suppose an external shock reduces export supply, such as a disruption in wheat-exporting regions. The new export supply is:

\[ ES' = -13 + P \]

The import price rises, imports decline, and consumer surplus in the importing country falls.

Code

# Egypt wheat example
# Qd = 20 - P
# Qs = P - 2
# ED = 22 - 2P
# Initial ES = -10 + 2P
# Shock ES = -13 + P

import pandas as pd

P_autarky = 11
Q_autarky = 9
CS_autarky = 0.5 * (20 - P_autarky) * Q_autarky
PS_autarky = 0.5 * (P_autarky - 2) * Q_autarky
TS_autarky = CS_autarky + PS_autarky

# Initial trade equilibrium: 22 - 2P = -10 + 2P
P_trade = 8
Qd_trade = 20 - P_trade
Qs_trade = P_trade - 2
imports_trade = Qd_trade - Qs_trade
CS_trade = 0.5 * (20 - P_trade) * Qd_trade
PS_trade = 0.5 * (P_trade - 2) * Qs_trade
TS_trade = CS_trade + PS_trade

# Shock equilibrium: 22 - 2P = -13 + P
P_shock = 35 / 3
Qd_shock = 20 - P_shock
Qs_shock = P_shock - 2
imports_shock = Qd_shock - Qs_shock
CS_shock = 0.5 * (20 - P_shock) * Qd_shock
PS_shock = 0.5 * (P_shock - 2) * Qs_shock
TS_shock = CS_shock + PS_shock

wheat_results = pd.DataFrame({
    "Scenario": ["Autarky", "Free trade", "After export-supply shock"],
    "Price": [P_autarky, P_trade, P_shock],
    "Domestic demand": [Q_autarky, Qd_trade, Qd_shock],
    "Domestic supply": [Q_autarky, Qs_trade, Qs_shock],
    "Imports": [0, imports_trade, imports_shock],
    "CS": [CS_autarky, CS_trade, CS_shock],
    "PS": [PS_autarky, PS_trade, PS_shock],
    "TS": [TS_autarky, TS_trade, TS_shock]
})

wheat_results.round(2)

	Scenario	Price	Domestic demand	Domestic supply	Imports	CS	PS	TS
0	Autarky	11.00	9.00	9.00	0.00	40.50	40.50	81.00
1	Free trade	8.00	12.00	6.00	6.00	72.00	18.00	90.00
2	After export-supply shock	11.67	8.33	9.67	-1.33	34.72	46.72	81.44

Code

P_vals = np.linspace(0, 15, 200)
ED = 22 - 2 * P_vals
ES_initial = -10 + 2 * P_vals
ES_shock = -13 + P_vals

plt.figure()
plt.plot(ED, P_vals, label="Egypt excess demand")
plt.plot(ES_initial, P_vals, label="ROW export supply")
plt.plot(ES_shock, P_vals, linestyle="--", label="ROW export supply after shock")
plt.scatter([imports_trade, imports_shock], [P_trade, P_shock])
plt.xlabel("Imports")
plt.ylabel("Price")
plt.title("Egypt wheat import market")
plt.legend()
plt.tight_layout()
plt.show()

A negative export-supply shock raises the import price and reduces import volume.

Lessons for trade policy

Import barriers may protect domestic producers, but they also create costs. The main lessons are:

Tariffs raise domestic prices and reduce consumer welfare.
Small-country tariffs reduce national welfare.
Quotas create rents and can be more restrictive than tariffs.
Tariff-rate quotas are common in agricultural trade.
Domestic production subsidies may be less distortionary than tariffs but require public funds.
Effective protection can be much higher than nominal protection.
Food-importing countries are vulnerable to world market shocks.

Key takeaway

Import barriers protect some domestic producers but usually reduce overall welfare. The largest burden often falls on consumers through higher prices. In agricultural trade, import barriers and supply shocks can have direct food-security implications, especially for countries that depend heavily on imported food.

Review questions

What is protectionism?
Distinguish between a specific tariff and an ad valorem tariff.
Why does a small-country tariff reduce national welfare?
What are the two components of deadweight loss from a tariff?
What is a quota rent?
Why can quotas become more restrictive than tariffs when demand increases?
What is a tariff-rate quota?
Why might a large country gain from a tariff in theory?
Why is the optimal tariff argument risky in practice?
What does the effective rate of protection measure?

Practice problem

Suppose a country imports rice. Domestic demand and supply are:

\[ Q_d = 120 - 2P \]

\[ Q_s = 2P \]

The world price is $P_w = 20$. The government imposes a tariff of $t = 10$.

Find domestic demand, domestic supply, and imports before the tariff.
Find domestic demand, domestic supply, and imports after the tariff.
Calculate the change in consumer surplus.
Calculate the change in producer surplus.
Calculate government revenue.
Calculate the net welfare effect.
Explain who gains and who loses.

--- title: "05. Trade Barriers for Importing Countries" --- ## Learning objectives By the end of this chapter, you should be able to: 1. Explain why governments use import barriers. 2. Distinguish between tariffs, quotas, tariff-rate quotas, domestic subsidies, and local content requirements. 3. Calculate the welfare effects of a small-country tariff. 4. Explain why quotas can be more restrictive than tariffs. 5. Calculate the effective rate of protection. 6. Use excess demand and export supply to interpret import-market shocks. ## Why this chapter matters Import barriers are among the most common instruments of trade policy. They can protect domestic producers, raise government revenue, and support political objectives. However, they usually raise prices for consumers and reduce national welfare. For agricultural trade, import barriers are especially important. Many countries protect food producers, regulate food imports, and use tariffs or quotas to manage sensitive farm sectors. This chapter explains the main tools and shows how to evaluate their welfare effects. ## Protectionism **Protectionism** refers to government policies that restrict trade in order to shield domestic producers from foreign competition. Common arguments for protection include: - protecting jobs, - supporting infant industries, - protecting national security, - responding to foreign subsidies, - preventing dumping, - raising government revenue, - reducing import dependence. These arguments may be politically powerful, but the welfare effects are not always favorable. A policy can help one group and hurt another group at the same time. :::: {.callout-note} ## Main idea Trade barriers usually redistribute income from consumers to producers and sometimes to the government. The key welfare question is whether the gains to protected groups are larger than the losses to consumers and society. :::: ## Tariffs A **tariff** is a tax on a traded product. Import tariffs are more common than export tariffs. There are three common types of tariff. | Type | Definition | Example | |---|---|---| | Specific tariff | Fixed monetary charge per unit | 10 dollars per imported bicycle | | Ad valorem tariff | Percentage of import value | 20 percent of the value of each imported bicycle | | Compound tariff | Combination of specific and ad valorem tariff | 5 dollars per unit plus 10 percent of value | Tariffs raise the domestic price of imported goods. This helps domestic producers but hurts consumers. ## Small-country tariff A **small country** cannot affect the world price of the imported good. It takes the world price as given. Let: - $P_w$ be the world price, - $t$ be the tariff per unit, - $P_d$ be the domestic price after the tariff. For a small country: $$ P_d = P_w + t $$ The tariff raises the domestic price from $P_w$ to $P_d$. ## Welfare effects of a small-country tariff When the tariff raises the domestic price: - consumers lose because they pay a higher price and buy less, - domestic producers gain because they sell more at a higher price, - the government gains tariff revenue, - society loses because of production and consumption distortions. The national welfare effect is: $$ \Delta W = \Delta CS + \Delta PS + \Delta GR $$ where: - $CS$ is consumer surplus, - $PS$ is producer surplus, - $GR$ is government revenue. For a small country, the tariff creates a **deadweight loss**. This has two parts: 1. **Production loss**: inefficient domestic production replaces cheaper imports. 2. **Consumption loss**: some consumers stop buying because the price is higher. :::: {.callout-important} ## Key result For a small importing country, a tariff reduces national welfare because the government revenue and producer gain are smaller than the consumer loss. :::: ## Worked example: a small-country tariff Suppose the domestic market has: $$ Q_d = 100 - 2P $$ $$ Q_s = 2P $$ The world price is: $$ P_w = 20 $$ The government imposes a tariff: $$ t = 5 $$ So the domestic price becomes: $$ P_d = 25 $$ Before the tariff: $$ Q_d = 100 - 2(20) = 60 $$ $$ Q_s = 2(20) = 40 $$ Imports are: $$ M = 60 - 40 = 20 $$ After the tariff: $$ Q_d = 100 - 2(25) = 50 $$ $$ Q_s = 2(25) = 50 $$ Imports are: $$ M = 50 - 50 = 0 $$ In this example, the tariff is high enough to eliminate imports. ## Python application: tariff welfare calculator ```{python} #| label: chp05-tariff-calculator #| echo: true import pandas as pd # Demand and supply functions: # Qd = a - bP # Qs = c + dP a = 100 b = 2 c = 0 d = 2 Pw = 20 t = 5 Pd = Pw + t # Demand and supply quantities Qd_free = a - b * Pw Qs_free = c + d * Pw M_free = Qd_free - Qs_free Qd_tariff = a - b * Pd Qs_tariff = c + d * Pd M_tariff = max(Qd_tariff - Qs_tariff, 0) # Choke price and supply intercept P_max = a / b P_min = -c / d if d != 0 else 0 # Surplus calculations CS_free = 0.5 * (P_max - Pw) * Qd_free PS_free = 0.5 * (Pw - P_min) * Qs_free GR_free = 0 TS_free = CS_free + PS_free + GR_free CS_tariff = 0.5 * (P_max - Pd) * Qd_tariff PS_tariff = 0.5 * (Pd - P_min) * Qs_tariff GR_tariff = t * M_tariff TS_tariff = CS_tariff + PS_tariff + GR_tariff summary = pd.DataFrame({ "Scenario": ["Free trade", "With tariff"], "Price": [Pw, Pd], "Qd": [Qd_free, Qd_tariff], "Qs": [Qs_free, Qs_tariff], "Imports": [M_free, M_tariff], "CS": [CS_free, CS_tariff], "PS": [PS_free, PS_tariff], "Government revenue": [GR_free, GR_tariff], "Total surplus": [TS_free, TS_tariff] }) summary ``` ```{python} #| label: chp05-tariff-changes #| echo: true changes = pd.DataFrame({ "Item": ["Change in CS", "Change in PS", "Change in government revenue", "Change in total surplus"], "Value": [ CS_tariff - CS_free, PS_tariff - PS_free, GR_tariff - GR_free, TS_tariff - TS_free ] }) changes ``` ## Visualizing the tariff effect ```{python} #| label: chp05-tariff-figure #| fig-cap: "A tariff raises the domestic price, reduces consumption, increases domestic production, and lowers imports." #| fig-width: 7 #| fig-height: 5 #| echo: true import numpy as np import matplotlib.pyplot as plt P = np.linspace(0, P_max, 200) Qd = a - b * P Qs = c + d * P plt.figure() plt.plot(Qd, P, label="Demand") plt.plot(Qs, P, label="Supply") plt.axhline(Pw, linestyle="--", label="World price") plt.axhline(Pd, linestyle=":", label="World price + tariff") plt.scatter([Qd_free, Qs_free, Qd_tariff, Qs_tariff], [Pw, Pw, Pd, Pd]) plt.xlabel("Quantity") plt.ylabel("Price") plt.title("Small-country tariff") plt.legend() plt.tight_layout() plt.show() ``` ## Import quotas An **import quota** is a direct limit on the quantity of imports. For example, a country may allow only 10,000 tons of wheat to be imported in a year. A quota has effects similar to a tariff: - it raises the domestic price, - it reduces consumption, - it increases domestic production, - it reduces imports, - it creates deadweight loss. The main difference is the treatment of the **quota rent**. ## Quota rents A quota creates a gap between the domestic price and the world price. The right to import becomes valuable. The extra profit earned by import-license holders is called **quota rent**. $$ \text{Quota rent} = (P_d - P_w) \times Q_{quota} $$ Who receives this rent depends on how the quota is administered. | Quota administration method | Who gets the rent? | |---|---| | Government auctions import licenses | Government | | Government gives licenses to domestic importers | Domestic importers | | Foreign exporters receive quota rights | Foreign exporters | | First come, first served | Early importers | :::: {.callout-warning} ## Why quotas can be more restrictive A tariff allows imports to rise when domestic demand increases. A quota fixes the maximum quantity of imports. If demand rises, the domestic price can rise sharply under a quota. :::: ## Tariff-rate quota A **tariff-rate quota** combines a quota and a tariff. A limited quantity of imports enters at a low tariff. Imports above that quantity face a higher tariff. This system is common in agricultural trade because many countries want to allow some market access while still protecting sensitive domestic producers. | Import quantity | Tariff rate | |---|---| | Within quota | Low tariff | | Above quota | High tariff | ## Large-country tariff A **large country** can affect the world price of the imported good. When a large importing country imposes a tariff, it reduces import demand. This may lower the foreign export price. The importing country may gain from an improvement in its terms of trade. The welfare effect of a large-country tariff is: $$ \Delta W = \text{terms-of-trade gain} - \text{efficiency loss} $$ A large-country tariff can theoretically improve national welfare if the terms-of-trade gain is larger than the deadweight loss. However, this result is fragile because other countries may retaliate. :::: {.callout-important} ## Policy caution The optimal tariff argument is theoretically valid for a large country, but it is risky in practice. Retaliation can create a trade war that makes all countries worse off. :::: ## Domestic production subsidy A domestic production subsidy is a payment to domestic producers in import-competing sectors. It encourages domestic production without raising the consumer price directly. For this reason, a production subsidy usually creates a smaller welfare loss than an equivalent tariff or quota. However, it is not free. The subsidy must be financed by taxpayers. | Policy | Consumer price rises? | Government budget cost? | Main beneficiary | |---|---|---|---| | Tariff | Yes | No, revenue increases | Producers and government | | Quota | Yes | Depends on license system | Producers and license holders | | Production subsidy | No | Yes | Producers | ## Local content requirements and standards A **local content requirement** forces firms to use a minimum share of domestic inputs. It protects domestic input suppliers but raises production costs. Government procurement policies may also favor domestic suppliers, even when imported products are cheaper. Health, safety, and technical standards may be legitimate. However, they can become trade barriers if they are designed or applied in a protectionist way. ## Effective rate of protection The **nominal tariff** measures protection on the final good. The **effective rate of protection** measures protection on domestic value added. This is important because producers often use imported inputs. The effective rate of protection is: $$ ERP = \frac{VA_d - VA_w}{VA_w} \times 100 $$ where: - $VA_d$ is domestic value added after tariffs, - $VA_w$ is value added at world prices. ## Worked example: cheese, milk, and starting culture Suppose producing 1 kg of cheese requires: - 10 liters of milk, - 10 grams of starting culture. World prices are: | Item | World price | |---|---:| | Cheese | 20 dollars per kg | | Milk | 1 dollar per liter | | Starting culture | 0.5 dollars per gram | The country imposes: | Item | Tariff | |---|---:| | Cheese | 20 percent | | Milk | 10 percent | | Starting culture | 10 percent | At world prices: $$ \text{Input cost} = 10(1) + 10(0.5) = 15 $$ $$ VA_w = 20 - 15 = 5 $$ With tariffs: $$ \text{Cheese price} = 20(1.20) = 24 $$ $$ \text{Milk cost} = 10(1)(1.10) = 11 $$ $$ \text{Starting culture cost} = 10(0.5)(1.10) = 5.5 $$ $$ VA_d = 24 - 11 - 5.5 = 7.5 $$ So: $$ ERP = \frac{7.5 - 5}{5} \times 100 = 50\% $$ Although the nominal tariff on cheese is 20 percent, the effective protection of domestic value added is 50 percent. ## Python application: effective rate of protection ```{python} #| label: chp05-erp-calculator #| echo: true import pandas as pd cheese_price = 20 milk_liters = 10 milk_price = 1 culture_grams = 10 culture_price = 0.5 scenarios = pd.DataFrame({ "Scenario": [ "Initial tariffs", "Double cheese and milk tariffs", "Double all tariffs" ], "Cheese tariff": [0.20, 0.40, 0.40], "Milk tariff": [0.10, 0.20, 0.20], "Culture tariff": [0.10, 0.10, 0.20] }) VA_world = cheese_price - (milk_liters * milk_price) - (culture_grams * culture_price) rows = [] for _, row in scenarios.iterrows(): output_domestic = cheese_price * (1 + row["Cheese tariff"]) milk_domestic = milk_liters * milk_price * (1 + row["Milk tariff"]) culture_domestic = culture_grams * culture_price * (1 + row["Culture tariff"]) VA_domestic = output_domestic - milk_domestic - culture_domestic ERP = (VA_domestic - VA_world) / VA_world * 100 rows.append({ "Scenario": row["Scenario"], "World value added": VA_world, "Domestic value added": VA_domestic, "ERP percent": ERP }) erp_results = pd.DataFrame(rows) erp_results ``` :::: {.callout-note} ## Interpretation Effective protection can be much larger than nominal protection when tariffs on the final product are high and tariffs on imported inputs are low. This is why economists focus on value added, not only the tariff on the final good. :::: ## Applied example: Egypt wheat imports and an external supply shock Food-importing countries are exposed to world market shocks. Suppose Egypt imports wheat from the rest of the world. Its domestic market is: $$ Q_d = 20 - P $$ $$ Q_s = P - 2 $$ Egypt's excess demand is: $$ ED = Q_d - Q_s = 22 - 2P $$ Suppose the rest of the world export supply is initially: $$ ES = -10 + 2P $$ The free-trade equilibrium is found by setting: $$ ED = ES $$ Now suppose an external shock reduces export supply, such as a disruption in wheat-exporting regions. The new export supply is: $$ ES' = -13 + P $$ The import price rises, imports decline, and consumer surplus in the importing country falls. ```{python} #| label: chp05-egypt-wheat #| echo: true # Egypt wheat example # Qd = 20 - P # Qs = P - 2 # ED = 22 - 2P # Initial ES = -10 + 2P # Shock ES = -13 + P import pandas as pd P_autarky = 11 Q_autarky = 9 CS_autarky = 0.5 * (20 - P_autarky) * Q_autarky PS_autarky = 0.5 * (P_autarky - 2) * Q_autarky TS_autarky = CS_autarky + PS_autarky # Initial trade equilibrium: 22 - 2P = -10 + 2P P_trade = 8 Qd_trade = 20 - P_trade Qs_trade = P_trade - 2 imports_trade = Qd_trade - Qs_trade CS_trade = 0.5 * (20 - P_trade) * Qd_trade PS_trade = 0.5 * (P_trade - 2) * Qs_trade TS_trade = CS_trade + PS_trade # Shock equilibrium: 22 - 2P = -13 + P P_shock = 35 / 3 Qd_shock = 20 - P_shock Qs_shock = P_shock - 2 imports_shock = Qd_shock - Qs_shock CS_shock = 0.5 * (20 - P_shock) * Qd_shock PS_shock = 0.5 * (P_shock - 2) * Qs_shock TS_shock = CS_shock + PS_shock wheat_results = pd.DataFrame({ "Scenario": ["Autarky", "Free trade", "After export-supply shock"], "Price": [P_autarky, P_trade, P_shock], "Domestic demand": [Q_autarky, Qd_trade, Qd_shock], "Domestic supply": [Q_autarky, Qs_trade, Qs_shock], "Imports": [0, imports_trade, imports_shock], "CS": [CS_autarky, CS_trade, CS_shock], "PS": [PS_autarky, PS_trade, PS_shock], "TS": [TS_autarky, TS_trade, TS_shock] }) wheat_results.round(2) ``` ```{python} #| label: chp05-egypt-wheat-figure #| fig-cap: "A negative export-supply shock raises the import price and reduces import volume." #| fig-width: 7 #| fig-height: 5 #| echo: true P_vals = np.linspace(0, 15, 200) ED = 22 - 2 * P_vals ES_initial = -10 + 2 * P_vals ES_shock = -13 + P_vals plt.figure() plt.plot(ED, P_vals, label="Egypt excess demand") plt.plot(ES_initial, P_vals, label="ROW export supply") plt.plot(ES_shock, P_vals, linestyle="--", label="ROW export supply after shock") plt.scatter([imports_trade, imports_shock], [P_trade, P_shock]) plt.xlabel("Imports") plt.ylabel("Price") plt.title("Egypt wheat import market") plt.legend() plt.tight_layout() plt.show() ``` ## Lessons for trade policy Import barriers may protect domestic producers, but they also create costs. The main lessons are: 1. Tariffs raise domestic prices and reduce consumer welfare. 2. Small-country tariffs reduce national welfare. 3. Quotas create rents and can be more restrictive than tariffs. 4. Tariff-rate quotas are common in agricultural trade. 5. Domestic production subsidies may be less distortionary than tariffs but require public funds. 6. Effective protection can be much higher than nominal protection. 7. Food-importing countries are vulnerable to world market shocks. ## Key takeaway Import barriers protect some domestic producers but usually reduce overall welfare. The largest burden often falls on consumers through higher prices. In agricultural trade, import barriers and supply shocks can have direct food-security implications, especially for countries that depend heavily on imported food. ## Review questions 1. What is protectionism? 2. Distinguish between a specific tariff and an ad valorem tariff. 3. Why does a small-country tariff reduce national welfare? 4. What are the two components of deadweight loss from a tariff? 5. What is a quota rent? 6. Why can quotas become more restrictive than tariffs when demand increases? 7. What is a tariff-rate quota? 8. Why might a large country gain from a tariff in theory? 9. Why is the optimal tariff argument risky in practice? 10. What does the effective rate of protection measure? ## Practice problem Suppose a country imports rice. Domestic demand and supply are: $$ Q_d = 120 - 2P $$ $$ Q_s = 2P $$ The world price is $P_w = 20$. The government imposes a tariff of $t = 10$. 1. Find domestic demand, domestic supply, and imports before the tariff. 2. Find domestic demand, domestic supply, and imports after the tariff. 3. Calculate the change in consumer surplus. 4. Calculate the change in producer surplus. 5. Calculate government revenue. 6. Calculate the net welfare effect. 7. Explain who gains and who loses.