Majority voting and Gini-based social welfare: testing the hypothesis of symmetry

Abstract

Majority voting accords with the class of social evaluation functions consistent with the Gini coefficient when income distributions are symmetric under a rank-dependent transformation (Rodríguez and Salas, 2014). Under this assumption, median income and the equally distributed equivalent income are the same, and the Gini coefficient is an affine function of the median–mean ratio. Despite the importance of these findings, the empirical plausibility of the symmetry hypothesis has not been tested yet. In this article, we contrast the symmetry assumption with an empirical exercise based on the Survey on Income and Living Conditions data set for the European Union in the period 2005–2007. We find that the symmetric condition is generally fulfilled.