Investigate the basis of free trade and its advantages and disadvantages including the theory of comparative advantage, the role of the World Trade Organisation, and the effects of trading blocs, free trade agreements and protection

What this dot point is asking

NESA wants you to explain why countries trade (comparative advantage), describe the gains from trade, understand the WTO and free trade agreements, and analyse the four main types of protection with diagrams. Trade questions are very high frequency in Section II and Section III.

The answer

Why countries trade: the theory of comparative advantage

The classic case for trade is comparative advantage, due to David Ricardo (1817). A country has a comparative advantage in producing a good when it can produce that good at lower opportunity cost than another country.

Worked example. Suppose Australia and Japan can each produce wheat or cars with one unit of labour:

Opportunity cost of one car in Australia: 5 tonnes of wheat (10/2). Opportunity cost of one car in Japan: 1 tonne of wheat (4/4).

Japan has the comparative advantage in cars (lower opportunity cost). Australia has the comparative advantage in wheat. Each country specialises in its comparative-advantage good and trades; both countries are better off than under autarky.

The trade exchange rate must lie between the two countries' domestic opportunity cost ratios (between 1 and 5 tonnes of wheat per car) for both to benefit.

The gains from trade

Trade according to comparative advantage delivers:

1. Specialisation and scale. Countries focus on what they do best, with larger production runs reducing average cost.
2. Wider consumer choice. Australian consumers can buy Japanese cars, French wine and Korean electronics that domestic producers cannot match.
3. Lower prices. Competition from imports disciplines domestic producers.
4. Technology transfer. Trade carries embodied technology (machinery imports) and disembodied technology (ideas, standards).
5. Higher productivity. Exposure to global best practice raises domestic firms' productivity over time.

The World Trade Organisation

The WTO is the multilateral body that administers world trade rules and dispute resolution. Created in 1995 as successor to the GATT. Three pillars: trade in goods, trade in services (GATS), and intellectual property (TRIPS). Decisions are by consensus among 164 member economies.

Successes: average tariffs on manufactures have fallen from around 40 percent in 1947 to under 5 percent by 2020 (WTO). The WTO Dispute Settlement Body has ruled on more than 600 cases.

Difficulties: the Doha Development Round (launched 2001) has effectively stalled. The WTO Appellate Body has been paralysed since 2019 because the United States has blocked new appointments. Member countries have shifted to bilateral and regional FTAs.

Free trade agreements

A free trade agreement (FTA) is a treaty between two or more countries that progressively eliminates tariffs and other barriers between them. Australia is party to 17 FTAs, including:

• ChAFTA (China-Australia, 2015)
• CPTPP (Trans-Pacific, 2018; 11 members)
• A-UKFTA (Australia-UK, 2023)
• AANZFTA (ASEAN-Australia-New Zealand, 2010)
• RCEP (Regional Comprehensive Economic Partnership, 2022; 15 members)

FTAs deepen trade but also create trade diversion (sourcing from a less efficient member in preference to a non-member) alongside trade creation (replacing domestic production with cheaper imports from a member).

Types of protection

1. Tariff

A tax on imports. Raises the price of imports, reduces import volume, raises domestic price, transfers some surplus from consumers to domestic producers and the government, and creates a deadweight loss.

2. Subsidy

A government payment to domestic producers. Shifts the domestic supply curve right, reduces the import price gap, transfers from taxpayers to producers, and creates a deadweight loss similar to a tariff (but no government revenue).

3. Quota

A quantitative limit on imports. Raises the domestic price like a tariff but the revenue goes to the importer holding the quota licence rather than the government.

4. Local content rules

Require firms to use a specified percentage of domestic inputs. Common in defence and automotive procurement. Distort input choice and raise production cost.

The tariff diagram

Draw the domestic demand and supply curves intersecting at the autarky equilibrium. Add a horizontal world price line below the autarky price. Add a tariff that lifts the price by the tariff amount.

• Gain to producers: rectangle on the supply side.
• Loss to consumers: trapezoid combining all four areas.
• Government revenue: middle rectangle.
• Deadweight loss: two triangles (production distortion plus consumption distortion).

The deadweight loss is the net welfare cost to the economy.

Recent trends

After three decades of liberalisation, world trade has entered a more protectionist phase. The US has imposed tariffs averaging 19 percent on roughly USD 360 billion of Chinese imports since 2018. The EU's Carbon Border Adjustment Mechanism (CBAM, 2026) levies a carbon-equivalent tariff on imports of cement, iron and steel, aluminium, fertilisers, electricity and hydrogen. Industrial policy subsidies (US Inflation Reduction Act 2022; EU Green Deal Industrial Plan) have raised concerns about renewed subsidy competition.

Common HSC traps

Confusing comparative with absolute advantage

Comparative advantage is about opportunity cost. Even if one country is absolutely worse at producing both goods, mutually beneficial trade is still possible.

Forgetting the deadweight loss

Markers expect the two-triangle DWL on every tariff diagram.

Treating FTAs as unambiguously good

Always raise trade diversion alongside trade creation.