IIT (Sectoral Marginal)
IIT (Aggregate Marginal)
Regional Market Share
|IIT (Sectoral Marginal)
The marginal sectoral IIT index tells us how much of the change in the volume of trade between two periods is intra-industry trade. Evaluating changes in IIT over time needs to be done carefully, because the IIT index can remain constant even as the volume of intra-industry trade expands.
One minus the ratio in which the numerator is obtained as the absolute value of the change in exports in a given product category less the change in imports in the same category, and a denominator as the sum of the absolute values of the changes in exports and imports in the category.
Range of values:
The index ranges from 0 to 1, with zero indicating pure inter-industry trade, and one indicating pure intra-industry trade.
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.