Why Nations Trade
Trade's deepest result is counterintuitive: nations gain from trade even if one is worse at everything.
Absolute advantage means producing more with the same resources. Comparative advantage means producing at the lowest opportunity cost in forgone alternatives.
Ana drafts contracts and types faster than her assistant, yet she hands off typing. Her hour typing costs a 300 euro contract; her assistant's hour costs little. Nations obey this same arithmetic.
| Absolute Advantage | Comparative Advantage | |
|---|---|---|
| Definition | Produce more with same resources | Produce at lower opportunity cost |
| Decides trade? | No | Yes |
| All goods? | One side can hold both | Impossible, costs are relative |
Key rule: Specialize where your opportunity cost is lowest. Both sides then consume beyond their production frontiers: gains from trade.
Barriers and Balances
Barriers. A tariff taxes imports. Domestic producers and the treasury gain, consumers pay more, and part of the loss evaporates as deadweight loss. A quota caps quantities, and non-tariff barriers use standards and licensing.
Common pitfall: Judging a tariff only by visible winners. Losses and deadweight loss spread thinly across consumers and exceed gains.
Trade balance, exports minus imports, reflects national saving and investment, not winning or losing. A deficit means foreigners finance domestic investment.
| Tariff | Quota | |
|---|---|---|
| Mechanism | Tax on imports | Quantity cap on imports |
| Treasury effect | Generates revenue | No direct revenue |
Protection persists because benefits concentrate on an organized few while costs spread across all consumers.