A new inequality measurement tool: The Vinci index

This paper presents a new inequality measurement tool that gives more weight to inequality at the lower end of the income distribution and offers a new way to synthesize the dispersion of the whole distribution. The proposed measure leverages the mean-dependent differentials that sum to the Gini coefficient and scales them by a type of differential that is exclusively concerned with the inequality between two incomes. The resulting index addresses the limitations of the Gini coefficient and possesses a set of desirable properties, including normalization, scale invariance, population invariance, transfer sensitivity, and weak decomposability.