Gini and entropy are the most use measures to gauge income inequalities. We show that each measure yields different subgroup decomposition techniques into within-group inequalities and between-group inequalities. Then, we show that the Gini index has been decomposed into many ways to bring out a...

Following Milanovic's (1997) paper [Economics Letters, vol. 56, p. 45-49], we propose a simple way to compute the Gini index when income y is a quadratic function of its rank among n individuals.