Calculation of the Index of Dissimilarity

This example considers 10 trucking companies and their respective share of the total number companies (X) and of the market (Y). In this case, there is an unequal distribution of traffic with the three largest companies accounting for 60% of the market. The largest company accounts for 25% of the market while the smallest accounts for only 2%. This distribution is fairly unequal with an index of dissimilarity (ID; the sum of all differences from the line of perfect equality, X-Y) of 0.325.