Income inequality measures involve two sub-classes of decomposable measures: those decomposed by sub-groups and those decomposed by income source. The former enables one to compute between- and within-group indices. The latter allows for gauging the inequality related to each factor of income...

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...