The theory of international trade is guided by the principle of comparative cost. This principle was propounded by David Richards.

The principle of comparative cost states that a country should specialize in the production of goods and services in which they have a greater comparative advantage or the least comparative disadvantage.

Below is an instance on the principle of comparative cost.

Now, let us assume we have two countries producing and exporting rice and beans respectively.

• On a daily basis, If country A produces 100 grams of rice and 300 grams of beans daily and country B produces 50 grams of rice and 150 grams of beans, then according to this principle, country A has an advantage over country B with regards rice and beans production; but better still, country A has a greater comparative advantage in the production of beans.

From the above instance, it can also be said that country B is at a disadvantage with regards to the production of rice and beans. Infact, it has a bigger comparative disadvantage with regards to beans production.

The point to note here is this: A country utilizing the principle of comparative cost will always produce quality goods and services at a cheaper cost.

No single country manufactures all the goods and services in our world. This implies that every country of the world relies on certain goods and services imported (or brought in) from other countries.

Foreign trade is defined as the exchange of goods, services and capital between two or more countries.

Foreign trade is also termed as international trade.

Please read more on foreign trade here