Development economists agree that increasing export diversification is a concomitant to economic development.  An accepted explanation for Africa’s export stagnation is its dependence on monoculture, and on small number of commodities.  Recently a large body of literature focuses on the relationship between economic growth and export specialization.  However, there does not exist one generally acceptable measure or index for the concept of “Specialization in International Trade”.  This paper suggest one such measure for specialization and its theoretical and conceptual framework are developed and applied to Singapore, South Korea, Malaysia, Mexico, Tunisia and Morocco, during the years of their take offs.