International Economics
International economics studies economic interactions across national borders — the patterns and gains from trade, trade policy, exchange rates, the balance of payments, and international monetary arrangements.
Scope
The field (JEL category F) divides into international trade (real flows of goods, services, and factors) and international finance (exchange rates, capital flows, and open-economy macroeconomics), with policy applications from tariffs to currency unions.
Sub-topics
Core questions
- Why do countries trade, and who gains?
- What determines the pattern of trade?
- What are the effects of trade policy (tariffs, quotas)?
- What determines exchange rates and the balance of payments?
- How should international monetary arrangements be designed?
Key concepts
- Comparative advantage
- Gains from trade
- Factor endowments
- Intra-industry trade
- Tariffs and trade policy
- Exchange rates
- Balance of payments
- Optimum currency area
Key theories
- Comparative advantage
- Ricardo showed that countries gain from trade by specializing according to comparative, not absolute, advantage — the foundational result of trade theory.
- Factor endowments (Heckscher-Ohlin)
- Ohlin explained trade patterns by differences in countries' factor endowments, linking trade to relative factor abundance.
- New trade theory
- Krugman showed how increasing returns and product differentiation generate intra-industry trade among similar economies, beyond comparative advantage.
- Optimum currency areas
- Mundell analysed the conditions under which regions benefit from sharing a currency, foundational for exchange-rate regimes and monetary unions.
History
International economics began with Ricardo's comparative advantage (1817) and was developed by the Heckscher-Ohlin factor-endowments model and the Stolper-Samuelson and factor-price-equalization theorems. Mundell's open-economy macroeconomics and optimum-currency-area theory shaped international finance from the 1960s, and Krugman's new trade theory and economic geography reshaped trade theory from the late 1970s.
Debates
- Free trade versus protection
- The case for gains from trade is weighed against distributional effects, infant-industry and strategic-trade arguments, and adjustment costs.
- Fixed versus flexible exchange rates
- Optimum-currency-area analysis frames the trade-offs between exchange-rate stability and independent monetary policy.
Key figures
- David Ricardo
- Bertil Ohlin
- Robert Mundell
- Paul Krugman
Related topics
Seminal works
- ricardo-1817
- ohlin-1933
- mundell-1961
- krugman-1979
Frequently asked questions
- What is comparative advantage?
- The principle that a country should specialize in producing what it can make at lower opportunity cost, gaining from trade even if it is less efficient at everything in absolute terms.
- What is an optimum currency area?
- A region for which the benefits of sharing a single currency (lower transaction costs) outweigh the cost of losing independent monetary policy, given labour mobility and economic similarity.