Dispersion, Asymmetry and the Gini Index of Inequality.

The paper shows that the value of the Gini Index of Inequality (Concentration) depends on the skewness of the income distribution. It i s first proved that the Gini Index belongs to the family of relative mean deviat ions. Then a new asymmetry index is defined which allows one to show that the Gini Index of symmetric distributions is always smaller or equal to one-half, whereas a necessary condition for the Gini Index to be greater than one-half is that the distribution be skewed to the right. Copyright 1987 by Economics Department of the University of Pennsylvania and the Osaka University Institute of Social and Economic Research Association.