What this lesson teaches
I can explain why countries specialise and trade, using comparative advantage.
Syllabus 9570, 3.3.1(b). Globalisation, International Trade and Economic Co-operation: Basis of free trade and specialisation
Make a guess
Country A can make both rice and chips with fewer workers than Country B. Can both still gain from trade?
- No. A is better at everything, so it gains nothing from B.
- Yes, if each specialises where its opportunity cost is lower.
- B gains, but A loses, because it gives up its better goods.
Show the answer
Yes, if each specialises where its opportunity cost is lower.
Gains come from comparative advantage, not absolute advantage. A gives up less to make one good, B to make the other, and trade lets both consume more.
Countries gain from specialising in what they produce at a lower opportunity cost, even if another country is better at everything.
A country has an absolute advantage in a good if it can produce more of it with the same resources.
A country has a comparative advantage if it can produce the good at a lower opportunity cost: it gives up less of other goods to make it.
If each country specialises in the good where it has a comparative advantage and trades, both can consume more than they could alone. This is true even if one country is better at producing everything.
Comparative advantage comes largely from factor endowments: the land, labour, capital and skills a country has. A country tends to have a comparative advantage in goods that use a lot of the factor it has in abundance. Land-rich countries export farm goods. Countries with many low-wage workers export labour-intensive goods such as garments. Countries rich in capital and skilled workers export goods that need machines, research and know-how.
Comparative advantage is not fixed. Investment adds capital, education and training add skills, and new technology changes which inputs a good needs. As a country's skills and wages rise, its opportunity cost of making labour-intensive goods rises: the same workers and machines could now make far more skill-intensive goods instead. So its advantage moves towards skill- and capital-intensive goods.
Singapore shows this shift. In the 1960s and 1970s, plentiful low-cost labour gave it an advantage in labour-intensive manufacturing such as garments and electronics assembly. From 1979, the government deliberately raised wages to push firms towards higher-value production, while investing in education and infrastructure. Labour-intensive work moved to lower-wage economies in the region.
Today Singapore's comparative advantage lies in high-value manufacturing, such as pharmaceuticals and semiconductors, and in services such as finance and logistics. It imports most of its food, where its opportunity cost, given scarce land, is high.
- Absolute advantage
- Produces more with the same resources.
- Comparative advantage
- Lower opportunity cost.
- Source
- Factor endowments: goods that use the abundant factor intensively.
- Over time
- More skills and capital raise the cost of labour-intensive goods, so the advantage moves up the value chain.
Worked example: An advantage that switches
Suppose that in 1975 Country K gives up 0.5 tonnes of chips to make one tonne of garments, and Country V gives up 0.8 tonnes. By 2025, after decades of education and investment, Country K gives up 1.1 tonnes of chips per tonne of garments, while Country V still gives up 0.8.
- 1975: K's opportunity cost of garments (0.5) is lower than V's (0.8), so K has the comparative advantage in garments.
- 2025: K's opportunity cost of garments (1.1) is now higher than V's (0.8), so V has the comparative advantage in garments.
- In chips the opposite holds: K now gives up only 1 / 1.1 = 0.91 tonnes of garments per tonne of chips, against V's 1 / 0.8 = 1.25, so K has the comparative advantage in chips.
- Nothing changed in V. K's own factor endowments changed, and that alone reversed the pattern of trade.
Watch out for this
A country that is better at producing everything gains nothing from trade.
Gains come from comparative advantage, which depends on opportunity cost. Both countries can still gain.
Check your understanding
What gives a country a comparative advantage in a good?
- Producing more of it per worker than any other country, using fewer resources.
- A lower opportunity cost of producing it than other countries.
- Having a large population, so it can make the good in bulk.
Show the answer
A lower opportunity cost of producing it than other countries.
Right. It gives up less of other goods to produce it.