Cambridge O Level Economics: Methods, reasons and consequences of protection (2281) – Revision Notes

These notes condense sections 6.2.4 to 6.2.6 of the Cambridge O Level Economics (2281) syllabus for examination in 2026, version 2: methods of protection, reasons for protection and consequences of protection. There are no tiers. For full explanations read the study guide, then test yourself with the practice questions. Other links: the Cambridge O Level Economics hub, the printable checklist and the free diagnostics. All numbers below are invented and illustrative.

Key definitions

Term	Definition
Protection	Any government step that helps home producers compete against foreign sellers
Tariff	A tax charged on imports (specific = set amount per unit; ad valorem = share of the value)
Import quota	A ceiling on the number of units that may be brought in during a period
Subsidy	Money paid by the government to producers, usually per unit
Embargo	A complete stop to trade with a country or in a good
Dumping	Selling abroad below cost or below the home-market price
Infant industry	A new industry with high costs because its output is small

Methods at a glance (6.2.4)

Method	Price to home buyers	Imports	Government finances	Main drawback
Tariff	Up	Down	Gains revenue	Buyers pay more
Quota	Up	Capped	Gains only if licences are sold	Foreign holders may keep the gain
Subsidy	Unchanged	Down a little	Pays out	Taxpayers carry the cost
Embargo	Up most	Zero	None	No choice, partners hurt

Method in steps: working out a tariff effect

1. Add the tariff to the world price to find the new home price.
2. Read quantity demanded and home output at the new price.
3. Imports = quantity demanded - home output.
4. Revenue = tariff per unit x imports after the tariff.
5. Compare each figure with free trade, using the original as the base for percentages.

Worked reminder. World price 80, tariff 20, so price 100. Demand falls from 940 to 800. Home output rises from 100 to 160. Imports = 800 - 160 = 640. Revenue = 20 x 640 = 12,800. Price rise = 20/80 = 25%. Demand change = -140/940 = -14.9%. Elasticity of demand over this range = -14.9 / 25 = -0.60.

Ad valorem reminder. A 30% tariff on a good priced at 40 adds 0.30 x 40 = 12, so the price is 52.

Subsidy reminder. A subsidy of 15 on 145 units costs 15 x 145 = 2,175. Buyers still pay the world price.

Quota reminder

A quota of 640 chairs in the same market gives the same home price of 100 as the tariff of 20, because imports of 640 fill the gap between demand (800) and home output (160). The extra 20 per chair, 20 x 640 = 12,800, goes to whoever holds the import licences. If foreign sellers hold them, the gain leaves the country. If the government sells them, it collects the money.

Embargo reminder

A ban on all imports leaves only home supply. In the example, price rises from 80 to 164, a rise of 105%, and quantity falls from 940 to 352. Buyers lose the most here, and the exporting country loses its whole market.

Reading a question on protection

Command word	What to write
Define	One precise sentence with the key term (for example “tax on imports”)
State	One short answer, no reasons
Calculate	Formula, working, then answer with units or a percentage sign
Explain	A point, then a reason, then an effect (because, so, which means)
Analyse	A chain of cause and effect, step by step
Evaluate	Both sides, then a judgement that depends on a stated condition

Context check. Use the country, product or firm named in the question. A generic answer on “protection” earns less than one that talks about the named product, its price and who buys it.

Reasons for protection (6.2.5)

Reason	Argument	Limit of the argument
Infant industry	Protect until economies of scale cut costs to the world price	Firm may stay inefficient if shielded for too long
Declining industry	Slow the fall so workers can retrain and move	Delays change, keeps resources in poor use
Strategic industry	Keep food, energy or defence supply secure	Costs consumers more, and many industries claim to be strategic
Avoiding dumping	Stop unfair pricing that could drive out home firms	Hard to prove; buyers lose cheap goods

Infant industry check. Average cost = total cost / output. If the world price is 60 and average cost is 80 at 1,000 units, 63 at 2,000 and 59 at 3,000, protection is needed until about 3,000 units.

Dumping check. A seller charges 38 abroad and 52 at home. A tariff of 14 closes the gap.

Consequences (6.2.6)

Group	Likely effect
Home consumers	Higher prices, less choice, lower real income
Home producers	More sales and jobs, often higher profit
Home government	Tariff revenue, or subsidy cost
Home economy	Net loss if protected producers cost more than imports; input users face dearer inputs
Trading partners	Fewer exports, lost jobs, possible retaliation

Welfare check for a tariff (figures from the worked reminder). Consumers lose 17,400. Producers gain 2,600. Government gains 12,800. Net loss = 17,400 - 2,600 - 12,800 = 2,000.

Effectiveness depends on:

• The elasticity of demand for imports: if it is elastic, imports fall a lot.
• The size of the tariff or the tightness of the quota.
• Whether home producers can raise output (elasticity of supply).
• Whether partners retaliate.
• Whether the policy is temporary or permanent.
• Smuggling and evasion.

Partner effect check. Exports of 840 at 80 = 67,200 fall to 640 at 80 = 51,200. Fall = 16,000, or 23.8%.

Putting protection in context

Protection is a trade-off. It helps a named group of producers and workers, often at the expense of a much larger group of buyers who each lose a little. That is why the gain is easy to see and the loss is easy to miss. When you judge a policy, ask three things: who gains, who pays, and for how long. A policy that ends on a set date is easier to defend than one with no limit.

Must-know distinctions

• Tariff versus quota: both raise home price, but a tariff gives revenue to the government.
• Tariff versus subsidy: a tariff makes consumers pay, a subsidy makes taxpayers pay.
• Tariff versus embargo: a tariff limits trade, an embargo ends it.
• Declining versus infant: one is falling and needs time to leave, the other is rising and needs time to grow.

Evaluation chains to rehearse

1. Tariff, so dearer imports, so buyers lose real income, so poorer households lose most. Judgement: depends on how much is spent on the good.
2. Protection, so partner exports fall, so partner retaliates, so home exporters lose sales. Judgement: the longer it lasts, the likelier the retaliation.
3. Infant protection, so output grows, so costs fall, so protection can end. Judgement: only convincing if there is a firm end date.

Quick self-test

1. Define an import quota.
2. A 20% ad valorem tariff is placed on an import priced at 150. What is the new price?
3. Name one way a quota differs from a tariff.
4. A subsidy of 8 per unit is paid on 250 units. What is the cost?
5. Imports of a good fall from 800 to 600 when price rises 10%. Calculate the elasticity of demand for imports.
6. State two reasons for protecting an industry.
7. Define dumping.
8. Give one cost of protecting a declining industry.
9. Explain one effect of a tariff on the exporters of a trading partner.
10. Tariff of 5 per unit on 900 imports. What is the revenue?

Answers

1. A ceiling on the number of units that may be brought in during a period.
2. 0.20 x 150 = 30, so 180.
3. A tariff gives the government revenue. A quota does not, unless the licences are sold.
4. 8 x 250 = 2,000.
5. Change in imports = -200/800 = -25%. Elasticity = -25 / 10 = -2.5.
6. Any two of infant industry, declining industry, strategic industry, avoidance of dumping.
7. Selling goods abroad for less than they cost to make, or for less than the seller charges at home.
8. It keeps resources in an industry that cannot compete, and buyers pay more.
9. Their goods cost more in the home market, so they sell fewer and may lose jobs.
10. 5 x 900 = 4,500.

Where marks are usually lost

• Giving a definition of dumping as “cheap imports”.
• Saying quotas raise revenue for the government without qualification.
• Writing a one-sided answer that only lists gains from protection.
• Basing a percentage on the wrong figure.
• Listing reasons for protection with no explanation of why they work.
• Forgetting trading partners when the question asks about them.
• Leaving out the elasticity link when asked how effective a tariff is.
• Confusing a subsidy to home producers with a tax on imports.

Official syllabus

Cambridge O Level Economics (2281) syllabus for examination in 2026, version 2, published by Cambridge University Press & Assessment: sections 6.2.4 Methods of protection, 6.2.5 Reasons for protection and 6.2.6 Consequences of protection.