Types of Trade Protection: IB Economics 4.2 notes

What trade protection is

Trade protection is any government policy that shields domestic producers from foreign competition by raising the price or restricting the quantity of imports. The four tools in the IB course are tariffs, quotas, subsidies to domestic producers, and administrative (or technical) barriers.

In every case the common thread is the same: domestic producers gain, domestic consumers pay higher prices and consume less, and society loses efficiency (a deadweight welfare loss). Who else gains depends on the tool, which is why you must compare them, not treat them as identical.

Tariffs

A tariff is a tax on imports. On the standard diagram the horizontal world-supply line shifts up by the tariff, so the domestic price rises from the world price Pw to Pw + tariff. At the higher price domestic supply expands, domestic demand contracts, and imports (the gap between them) shrink.

Stakeholder effects: consumers lose surplus (higher price, less consumed); domestic producers gain surplus and output; the government earns tariff revenue equal to the tariff per unit times the quantity of imports; foreign exporters sell less. Two deadweight-loss triangles remain, a production-inefficiency triangle (high-cost domestic output replacing cheap imports) and a consumption-inefficiency triangle (consumers priced out).

Quotas

A quota is a legal limit on the physical quantity of a good that may be imported. It also raises the domestic price and expands domestic output, so consumers lose and domestic producers gain in the same direction as a tariff.

The key difference is the revenue. With a quota there is no automatic government revenue; instead the price mark-up on the permitted imports (quota rents) usually goes to whoever holds the import licences, often the foreign exporters or licence-holders, rather than the state. That is a common exam distinction: a tariff earns the government revenue, a quota generally does not.

Subsidies to domestic producers

A production subsidy is a per-unit payment from the government to domestic producers, which lowers their costs and shifts the domestic supply curve to the right (downward). Domestic output rises and imports fall, but note the market price does not rise, so consumers are not directly penalised the way a tariff hits them.

The cost falls on the government (and therefore taxpayers): total subsidy spending equals the subsidy per unit times the new domestic quantity. There is still a welfare loss because higher-cost domestic production replaces cheaper imports. The EU Common Agricultural Policy is the classic real-world case of large producer subsidies distorting trade.

Administrative and technical barriers

Administrative barriers restrict imports through rules rather than price or quantity caps: complex customs paperwork, strict health, safety, labelling or environmental standards, and product specifications that foreign firms find costly to meet. They raise foreign firms' costs and delay or block entry.

They are harder to draw and quantify but have the same broad effect: fewer imports, protected domestic producers, and consumers facing less choice. They are politically convenient because they can be presented as protecting health or safety rather than as protectionism.

Tariff calculation worked example (HL)

Suppose the world price of a good is $10. At $10 domestic demand is 100 units and domestic supply is 40, so imports are 60. The government imposes a $2 tariff, raising the price to $12. Domestic supply rises to 50, demand falls to 90, so imports shrink to 40.

Government revenue = tariff x imports after tariff = $2 x 40 = $80. The gain in producer surplus is the supply-side trapezoid = (40 + 50)/2 x $2 = $90. The loss in consumer surplus is the demand-side trapezoid = (100 + 90)/2 x $2 = $190.

The deadweight welfare loss is what consumers lose that no one recaptures: $190 - $90 (producers) - $80 (government) = $20. Check with the triangles: production distortion = 0.5 x (50 - 40) x $2 = $10, plus consumption distortion = 0.5 x (100 - 90) x $2 = $10, total $20. Always show this arithmetic in an HL answer.

Common Paper mistakes

Do not say a quota earns government revenue: normally it does not, the quota rent goes to licence-holders. Do not say a producer subsidy raises the price to consumers: it lowers producers' costs, so the consumer price does not rise the way a tariff's does.

When calculating tariff revenue, use imports after the tariff (the shrunken quantity), not the free-trade import level. And label both deadweight-loss triangles: many answers show only one.

How this is examined

• HL Paper 3 loves the tariff welfare calculation: memorise the sequence (new price, new quantities, revenue, consumer-surplus loss, producer-surplus gain, deadweight loss) and show every number.
• On Paper 1, draw the tariff as an upward shift of the world-supply line and clearly shade producer gain, government revenue and the two welfare-loss triangles separately.
• The highest-value comparison in evaluation is tariff vs subsidy vs quota by who bears the cost: consumers (tariff, quota) versus taxpayers (subsidy) and who gets any revenue.
• Name a real policy (EU CAP subsidies, US steel tariffs) as your real-world example rather than describing protection in the abstract.

Key terms

tariffimport quotasubsidyprotectionismfree trade