The revealed comparative advantage (RCA) is an index used in international economics for calculating the relative advantage or disadvantage of a certain country in a certain class of goods or services as evidenced by trade flows.
is defined by: That is, the RCA is equal to the proportion of the country's exports that are of the class under consideration,
If RCA is less than unity, the country is said to have a comparative disadvantage in the commodity or industry.
The concept of revealed comparative advantage is similar to that of economic base theory, which is the same calculation, but considers employment rather than exports.
Example: in 2010, soybeans represented 0.35% of world trade with exports of $42 billion.
Because 7.9/0.35 = 22, Brazil exports 22 times its "fair share" of soybean exports, and so we can say that Brazil has a high revealed comparative advantage in soybeans.
Obtain RCA for predefined Product Groups like SITC Revision 2 Groups, Sector classification based on HS or UNCTAD's Stages of processing in in WITS Indicators by Product Group page.