On a generalisation of the Gini coefficient

The paper uses a set of axioms to characterise a one-parameter class of inequality measures which includes the Gini coefficient. An innovation is the use of an independence axiom; the remaining axioms are standard. The measures characterised, which we call I-Ginis, form a class distinct from the well-known S-Ginis of Donaldson and Weymark (Journal of Economic Theory, 1980, 22, 67-86), which also constitute a one-parameter generalisation of the Gini coefficient. (The relationship between the two classes is explored in a note.) A one-parameter class of poverty measures, derived in a manner similar to the I-Ginis, and closely related to Sen's poverty measure, is also characterised.