In the context of Social Welfare and Choquet integration, we briefly review, on the one hand, the classical Gini inequality index for populations of n ≥ 2 individuals, including the associated Lorenz area formula, and on the other hand, the k-additivity framework for Choquet integration introduced by Grabisch, particularly in the additive and 2-additive symmetric cases.We then show that any 2-additive symmetric Choquet integral can be written as the difference between the arithmetic mean and a multiple of the classical Gini inequality index, with a given interval constraint on the multiplicity parameter. In the special case of positive parameter values this result corresponds to the well-known Ben Porath and Gilboa’s formula for Weymark’s generalized Gini wel