Abstract
The paper is an examination of Balassa’s ‘revealed comparative advantage’ (RCA). The results of researches show that when using the RCA, it should always be attuned in such a way, that it becomes symmetric.This paper consists of three major parts i.e. theory, analytical tool and case studies of comparative advantage. First we evaluate the theory and various empirical measures. Then this analytical tool is applied to analyze exported product. The results indicate that Iran had not comparative advantage in export of walnut, almond hazelnut, apple, orange. To increase competitiveness, we suggest several policy recommendations such as increasing agricultural productivity, promoting the development of indigenous technological capabilities, and reducing the cost of doing business. The conclusion is based on a theoretical discussion of the properties of the measure, and on convincing empirical evidence, according to the Balassa index.The index for 2007 shows that Iran does not have a comparative advantage in export of walnut, almond hazelnut, apple and orange and reduced its market share in these products.