Journal of Probability and Statistics
Volume 2010 (2010), Article ID 718905, 26 pages
Research Article

Zenga's New Index of Economic Inequality, Its Estimation, and an Analysis of Incomes in Italy

1Dipartimento di Metodi Quantitativi per le Scienze Economiche e Aziendali, Università di Milano, Bicocca 20126, Milan, Italy
2Department of Statistical and Actuarial Sciences, University of Western Ontario, London, ON, N6A 5B7, Canada

Received 2 October 2009; Accepted 28 February 2010

Academic Editor: Madan L. Puri

Copyright © 2010 Francesca Greselin et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


For at least a century academics and governmental researchers have been developing measures that would aid them in understanding income distributions, their differences with respect to geographic regions, and changes over time periods. It is a fascinating area due to a number of reasons, one of them being the fact that different measures, or indices, are needed to reveal different features of income distributions. Keeping also in mind that the notions of poor and rich are relative to each other, Zenga (2007) proposed a new index of economic inequality. The index is remarkably insightful and useful, but deriving statistical inferential results has been a challenge. For example, unlike many other indices, Zenga's new index does not fall into the classes of L-, U-, and V-statistics. In this paper we derive desired statistical inferential results, explore their performance in a simulation study, and then use the results to analyze data from the Bank of Italy Survey on Household Income and Wealth (SHIW).