Comparative advantage.

The idea that a country gains by producing what it gives up least to make, then trading, even if a partner is better at everything.

Drafted with AI assistance. Not yet reviewed by a person · Last updated August 23, 2026

Source: World Bank

In plain English

Comparative advantage is about opportunity cost: what a producer sacrifices in one good to make another, rather than raw efficiency. If one country is more efficient at producing everything, it still cannot produce everything at once, so it concentrates where its edge is largest and trades for the rest. Both sides can end up with more total output than they could produce alone. The model assumes resources move between industries reasonably easily, which is where real economies push back. Gains from trade are aggregate, and specific workers and towns can lose even when a country gains.

Most useful ages

20 to 70

01Why it matters

This is the economic case behind free trade, and its assumption that displaced workers move to other industries is exactly where the political fight over trade policy lives.

02The math, step by step

Country A makes 10 shirts or 5 laptops per worker. Country B makes 4 shirts or 4 laptops. A gives up half a laptop per shirt; B gives up a full laptop per shirt. A holds the comparative advantage in shirts even though it is better at both, so A makes shirts and B makes laptops.

Illustrative example. The amounts here are hypothetical, chosen to show how the math works, not real quoted rates or figures.

03What this is NOT

Do not confuse with Absolute advantage

Absolute advantage means producing more of something with the same resources. Comparative advantage means producing it at a lower opportunity cost. A country can hold absolute advantage in every good and still have comparative advantage in only some, which is the whole point.