Explain economic unions, common markets and trading blocs
The idea
Regional trading blocs deepen integration in steps. A free trade area removes barriers among members while each keeps its own tariffs on outsiders. A customs union adds a common external tariff. A common market adds free movement of labour and capital. An economic union adds common institutions and coordinated economic policy, and a monetary union adds a single currency. Countries join for larger markets, economies of scale, stronger competition, specialisation and political cooperation. The costs are real too: trade diversion, where imports switch from an efficient outsider to a costlier member only because the tariff has gone, and a loss of national policy autonomy, sharpest in a monetary union, where a member gives up its own interest rate and exchange rate as tools for adjusting to shocks.
A practice question
A customs union differs from a free trade area because its members also:
- allow free movement of labourWhy not: Free movement of labour and capital is the step that turns a customs union into a common market.
- adopt a common external tariff — correct
- share a single currencyWhy not: A common currency belongs to a monetary union, the most integrated form of regional agreement.
A free trade area removes barriers among members but lets each set its own tariffs on outsiders. A customs union adds a shared tariff on non-members, which stops goods entering via the lowest-tariff member.
A harder one
Which is a principal motivation for countries to form a regional trading bloc?
- Raising tariffs among the member countriesWhy not: Blocs lower barriers among their members; higher internal tariffs would defeat the purpose.
- Guaranteeing each country's trade balanceWhy not: No trade agreement guarantees a balance; members typically run surpluses with some partners and deficits with others.
- Larger markets that allow economies of scale — correct
Removing barriers among members widens the market each firm can serve, allowing economies of scale, greater competition and specialisation. Blocs can also strengthen political cooperation among neighbours.
The hardest tier
Before joining a customs union, country A imported a good from non-member C at 10 plus a 30% tariff. After joining, A buys it tariff-free from member B at 12. This shift is best described as:
- trade diversion, raising the resource cost — correct
- trade creation, lowering the resource costWhy not: Trade creation replaces higher-cost supply with lower-cost supply; here the world's cheapest producer, C at 10, is displaced by B at 12.
- neither, since A's consumers pay lessWhy not: The domestic price does fall from 13 to 12, but the good is now produced less efficiently and A also loses its tariff revenue of 3.
With the tariff C's good cost 13 in A, so B at 12 wins once internal tariffs go. But B's true cost of 12 exceeds C's 10: imports are diverted from the more efficient non-member, a known cost of regional blocs.
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