Calculation of the Index of Dissimilarity
This example considers 10 airports and their respective share of the total number airports (X) and of the traffic (Y). In this case, there is an unequal distribution of traffic with the three largest airports accounting for 60% of the market. The largest airport 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.