IIT (Sectoral Marginal)
IIT (Aggregate Marginal)
Regional Market Share
The sectoral Hirschmann index is a measure of the sectoral concentration of a region’s exports. It tells us the degree to which a region
or country’s exports are dispersed across different economic activities. High concentration levels are sometimes interpreted as an indication of
vulnerability to economic changes in a small number of product markets. Over time, decreases in the index may be used to indicate broadening of the
The sectoral Hirschmann index is defined as the square root of the sum of the squared shares of exports of each industry in total exports for the region under study.
Range of values:
Takes a value between 0 and 1. Higher values indicate that exports are concentrated in fewer sectors. Value of 1 indicates that only a single product is exported.
For further note on this indicator, including an example and formula, see the relevant section of Trade Statistics in Policymaking: A Handbook of Commonly Used Trade Indices and Indicators.