The diversification index signals whether the structure of imports by product of a given country or group of countries differ from the structure of product of the world. Diversification index that ranges from 0 to 1 reveals the extent of the differences between the structure of trade of the country or country group and the world average. The index value closer to 1 indicates a bigger difference from the world average. It is constructed as the inverse of a Herfindahl index, using disaggregated exports at 4 digits (following the STIC3). This index is a modified Finger-Kreinin measure of similarity in trade. For more information, please consult the article of Finger, J. M. and M. E. Kreinin (1979), “A measure of ‘export similarity’ and its possible uses” in the Economic Journal , 89: 905-12.