The Generalized Beta Distribution as a Model for the Distribution of Income: Estimation of Related Measures of Inequality

Abstract

The generalized beta (GB) is considered as a model for the distribution of income. It is well known that its special cases include Dagum’s distribution along with the Singh-Maddala distribution. Related measures of inequality such as the Gini Coefficient, Pietra Index, or Theil Index are expressed in terms of the parameters of the generalized beta. This paper also explores the use of numerical integration techniques for calculating inequality indexes. Numerical integration may be useful since in some cases it may be computationally very difficult to evaluate the equations that have been derived or the equations are not available. We provide examples from the distribution of family income in the United States for the year 2000.