# International Trade

> CIE A-Level Economics · CIE 9708
> Source: https://www.owlsprep.com/study/cie-9708-u7-overview/
> Weight: 12-15% of overall exam

This unit explores why countries trade, the mutual gains from specialisation, arguments for and against trade barriers, and the international frameworks governing global trade. It is heavily tested in both MCQ and essay sections.

**Prerequisites:** [Opportunity cost and production possibility frontiers (PPFs)](https://www.owlsprep.com/study/cie-9708-u2-opportunity-cost-ppf/)

## Learning objectives

- Explain the basis of mutually beneficial gains from trade using absolute and comparative advantage models
- Calculate and interpret the terms of trade and how it distributes trade gains between countries
- Evaluate economic arguments for and against free trade and protectionism
- Analyse the micro and macro effects of different types of protectionist policies
- Explain the roles of the WTO and different forms of regional trade integration

## Unit at a Glance

This unit follows a logical arc from core economic theory to real-world policy and global institutions. We start by building the foundational argument for free trade, using the concept of opportunity cost to explain how specialisation can make all trading countries better off.

Next, we examine how the gains from trade are distributed between countries via terms of trade, then explore the ongoing policy debate between free trade and protectionism. We finish by covering the global and regional institutions that shape modern trade flows: the World Trade Organization and regional trading blocs.

The unit is split into 6 connected sub-topics:
- [Absolute and comparative advantage](https://www.owlsprep.com/study/cie-9708-u7-absolute-and-comparative-advantage/) — Introduces the core theories of specialisation and mutually beneficial trade between countries.
- [Terms of trade](https://www.owlsprep.com/study/cie-9708-u7-terms-of-trade/) — Explains how gains from trade are split between trading partners, including calculation of the terms of trade index.
- [Free trade vs protectionism](https://www.owlsprep.com/study/cie-9708-u7-free-trade-vs-protectionism/) — Evaluates the key economic arguments for and against protectionism and for free trade.
- [Types of protectionist policies](https://www.owlsprep.com/study/cie-9708-u7-types-of-protectionist-policies/) — Covers the welfare and distributional effects of tariffs, quotas, subsidies and other trade barriers.
- [World Trade Organization](https://www.owlsprep.com/study/cie-9708-u7-world-trade-organization/) — Explains the structure, core principles and role of the WTO in global trade governance.
- [Trading blocs and trade integration](https://www.owlsprep.com/study/cie-9708-u7-trading-blocs-and-trade-integration/) — Analyses different types of regional trade integration and their effects on members and non-members.

## Common pitfalls

- **Wrong:** Confusing absolute advantage with comparative advantage when determining specialisation patterns
  - Why it fails: Absolute advantage compares total output, while comparative advantage relies on opportunity cost, which is the correct determinant of trade patterns
  - Correct: Always compare opportunity costs to identify which good a country should specialise in
- **Wrong:** Claiming all protectionist policies are always economically harmful for all countries
  - Why it fails: Protectionism can have short-term benefits for domestic employment and strategic long-term benefits for developing economies
  - Correct: Use balanced evaluation to weigh the deadweight loss costs against any potential benefits of protectionism
- **Wrong:** Treating all trading blocs as identical forms of integration
  - Why it fails: Different levels of integration have distinct features and different effects on trade and welfare
  - Correct: Memorise the key differences between free trade areas, customs unions and common markets

## Cheatsheet

| Concept | Key Rule / Formula |
| --- | --- |
| Comparative Advantage | A country has comparative advantage if it has lower opportunity cost of production than its trading partner |
| Terms of Trade Index | $\text{ToT} = \frac{\text{Export Price Index}}{\text{Import Price Index}} \times 100$ |
| Tariff Welfare Effect | Creates deadweight loss, benefits domestic producers, raises government revenue, harms consumers |
| Quota vs Tariff | Quotas generate quota rent for importers; tariffs generate revenue for the government |
| WTO Core Principle | Most-favoured nation: non-discrimination between all member trading partners |
| Customs Union vs FTA | Customs unions have a common external tariff; free trade areas do not |

## What's next

Begin this unit with the core theory of comparative advantage, the foundation for all further analysis of trade policy and global trade institutions. Work through each sub-topic in order to build your understanding step by step. Once you complete all sub-topics in this unit, you can progress to the next unit on open macroeconomics covering balance of payments and exchange rates.

- [Absolute and comparative advantage](https://www.owlsprep.com/study/cie-9708-u7-absolute-and-comparative-advantage/)
- [Terms of trade](https://www.owlsprep.com/study/cie-9708-u7-terms-of-trade/)
- [Free trade vs protectionism](https://www.owlsprep.com/study/cie-9708-u7-free-trade-vs-protectionism/)

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