We provide a simple proof of Foster's (1983) characterization of the Theil inequality index.

It is possible to partially order cities with two ethnic groups according to the Lorenz criterion. Similarly, it is possible to partially order cities according to the informativeness of neighborhoods about the ethnic groups of its inhabitants. We show the equivalence of these two orders for the...

We identify an ordinal decomposability property and use it, along with other ordinal axioms, to characterize the Theil inequality ordering.