The first name that an Economics student is likely to encounter is Adam Smith. The second name is usually David Ricardo, the proponent of Comparative Advantage.

As a quick summary, Comparative Advantage states that even if a country makes every possible good more efficiently than other countries, it should still concentrate on the goods it is best at producing and engage in trade to supply itself with the rest.

The example Ricardo gave was the trade between Portugal and England of Wine and Cloth. Ricardo said that it was easier to produce both wine and cloth in Portugal than it was in England, but it was beneficial to both countries for Portugal to concentrate on wine, while England produced cloth (due to relative costs), and they subsequently could trade with each other. The problem with this theory is that it was 100% wrong.

Portugal was an extremely inefficient wine producer, but much of its wine production was controlled by the British (which is why many types of Port still have English names). During this time period, England was at war with France, which had been its main supplier of wine heretofore. Because of this, England imposed volume tariffs on French wine and offered cheaper deals on cloth to Portugal in exchange for its wine. Therefore, tariffs and protectionism are what brought about the Wine and cloth trade between Portugal and England, not comparative advantage.

So it is interesting to note that while Comparative Advantage remains a valid economic theory, its initial premise was entirely incorrect.