ECON6023 · International Trade
Trade Agreements and the Political Economy of Protection
Week 12 examines why governments protect despite the aggregate welfare cost, and how the WTO and regional trade agreements shape outcomes, distinguishing trade creation from trade diversion. The large-country tariff game as a prisoner's dilemma and the trade-creation-vs-diversion calculation are the concepts most likely to appear as a short applied or discussion exam question.
What this chapter covers
- 01Political economy of protection: concentrated producer benefits vs diffuse consumer costs
- 02GATT (1947) → WTO; Most-Favoured-Nation (MFN) principle; anti-dumping and safeguard clauses; dumping defined
- 03The large-country tariff game as a prisoner's dilemma: the Nash equilibrium is mutual tariffs, worse than free trade
- 04Multilateral institutions as a way to escape the bad tariff-game equilibrium
- 05Free-trade area (own external tariffs, rules of origin needed) vs customs union (common external tariff)
- 06Trade creation: importing from a lower-cost member a good you used to make yourself (welfare gain)
- 07Trade diversion: switching imports from a lower-cost outsider to a higher-cost member (possible welfare loss)
- 08Net RTA effect = trade creation vs trade diversion; trade and the environment
Trade creation vs trade diversion in a regional trade agreement
- +1Before the agreement. With the 4 tariff on everyone, the tariff-inclusive prices are partner 10 + 4 = 14 and outsider 8 + 4 = 12. Home buys from the outsider at 12 and collects 4 of tariff revenue per unit.
- +1After the agreement. The tariff on the partner is removed (partner price 10) but kept on outsiders (12). Home now buys from the partner at 10, and the price consumers pay falls from 12 to 10.
- +1Classification. Home has switched its source from the lowest-cost outsider (true resource cost 8) to a higher-cost partner (10). Because the shift is toward a higher-cost supplier, this is trade DIVERSION, not trade creation — real resource cost per unit rises from 8 to 10.
- +1Net welfare. There is a consumer gain from the lower price (12 → 10), but the government loses the 4 of tariff revenue it used to collect, and the good is now made with more real resources (10 vs 8). The net effect is ambiguous: a regional trade agreement raises welfare only if its trade creation outweighs its trade diversion.
Key terms
- Trade creation
- When a regional trade agreement lets a member import a good from a lower-cost member that it used to produce domestically at higher cost — a welfare gain from more efficient sourcing.
- Trade diversion
- When a preference causes a member to switch imports from a lower-cost outside country to a higher-cost member country, raising the real resource cost and forgoing tariff revenue — a possible welfare loss.
- Free-trade area
- An agreement where members remove tariffs on each other but keep their own external tariffs, requiring rules of origin to stop trans-shipment through the lowest-tariff member.
- Customs union
- A free-trade area plus a common external tariff, so rules of origin are unnecessary because all members charge outsiders the same tariff.
- Most-Favoured-Nation (MFN)
- The WTO principle that a country must extend any tariff concession to all members equally (GATT Article I). Regional trade agreements are the sanctioned exception to MFN.
- Prisoner's dilemma (tariff game)
- The large-country tariff game whose unique Nash equilibrium is mutual tariffs, worse for both countries than mutual free trade. Multilateral institutions (WTO/GATT) exist to escape this outcome.
Trade Agreements and the Political Economy of Protection FAQ
What is the difference between trade creation and trade diversion?
Trade creation replaces high-cost domestic production with lower-cost imports from a partner — an efficiency gain. Trade diversion replaces low-cost imports from an outsider with higher-cost imports from a partner, purely because the partner enjoys a tariff preference — an efficiency loss, plus lost tariff revenue. To tell them apart, compare the true (pre-tariff) resource costs across suppliers; a regional trade agreement is beneficial on net only if creation outweighs diversion.
Why is the large-country tariff game a prisoner's dilemma?
Each large country has a private incentive to impose a tariff to improve its terms of trade, so 'impose a tariff' is a dominant strategy — the unique Nash equilibrium is mutual tariffs. But mutual tariffs leave both countries worse off than mutual free trade, exactly the prisoner's-dilemma structure. Multilateral institutions like the WTO, built on the MFN principle, let countries commit to the cooperative free-trade outcome they cannot reach unilaterally.
Can AI help me with trade-agreement questions?
Yes. Sia can work a trade-creation-versus-diversion example, set up the tariff-game payoff matrix, and explain the free-trade-area-versus-customs-union distinction step by step, then set fresh practice. It explains the method and checks your reasoning; it does not do graded assessment, and USyd academic-integrity rules apply. Confirm exam coverage on Canvas.
Why do governments protect if a tariff lowers aggregate welfare?
Because the political calculus differs from the welfare calculus. A tariff's benefits are concentrated on a small group of producers who lobby hard, while its costs are spread thinly across many consumers who each lose little and do not organise. So protection can be politically rational even when it lowers total welfare — the political economy of protection that this chapter formalises.
Exam move
Focus on the two examinable set pieces: the trade-creation-versus-diversion calculation (always compare pre-tariff resource costs, and note the lost tariff revenue) and the large-country tariff game as a prisoner's dilemma that the WTO exists to escape. Learn the free-trade-area-versus-customs-union distinction and the role of rules of origin. Be ready to explain the political economy of protection (concentrated benefits, diffuse costs) in a short paragraph. This chapter ties the policy models back to real institutions, so link each concept to an institution (GATT/WTO, MFN, RTAs). Confirm exam timing on Canvas.
Working through Trade Agreements and the Political Economy of Protection in ECON6023? Sia is AskSia’s AI Economics tutor — ask any ECON6023 Trade Agreements and the Political Economy of Protection question and get a clear, step-by-step explanation grounded in how ECON6023 is taught and assessed. Read this chapter free, then take your hardest questions to Sia.
