Book excerpt: First published in 1971, this is a study of the application of the economic theory of integration in developing countries attempts to assess the development of common markets and free trade areas in the contemporary developing world. The book synthesises various revisions of the old theory of the customs union, tackling the process of elaborating an appropriate theory for developing countries. The reissue will be of interest to those concerned with International Trade and Development Economics, as well as those interested in the development of the Caribbean region.