The Ricardian Model - International Trade

The Ricardian model provides an introduction to international trade theory. This most basic model of trade involves two countries, two goods, and one factor of production, labor. Differences in relative labor productivity across countries give rise to international trade. This Ricardian model, simple as it is, generates important insights concerning comparative advantage and the gains from trade. These insights are necessary foundations for the more complex models presented in later chapters.

The text exposition begins with the examination of the production possibility frontier and the relative prices of goods for one country. The production possibility frontier is linear because of the assumption of constant returns to scale for labor, the sole factor of production. The opportunity cost of one good in terms of the other equals the price ratio since prices equal costs, costs equal unit labor requirements times wages, and wages are equal in each industry.

After defining these concepts for a single country, a second country is introduced which has different relative unit labor requirements. General equilibrium relative supply and demand curves are developed. This analysis demonstrates that at least one country will specialize in production. The gains from trade are then demonstrated with a graph and a numerical example. The intuition of indirect production, that is "producing" a good by producing the good for which a country enjoys a comparative advantage and then trading for the other good, is an appealing concept to emphasize when presenting the gains from trade argument. Students are able to apply the Ricardian theory of comparative advantage to analyze three misconceptions about the advantages of free trade. Each of the three "myths" represents a common argument against free trade and the flaws of each can be demonstrated in the context of examples already developed in the chapter.

While the initial intuitions are developed