The origins of the Gini index: extracts from Variabilità e Mutabilità (1912) by Corrado Gini

The scope of this paper is to celebrate the 100th anniversary of the Gini index by providing the original formulae. Corrado Gini introduced his index for the first time in a 1912 book published in Italian under the name of “Variabilità e Mutabilità” (Variability and Mutability). This article provides selected extracts of Part I of the book dedicated to measures of variability. We find that Gini proposed no less than 13 formulations of his index, none of which is known today to the large public. We also find that Gini anticipated some of the developments that derived from the study of his index. Copyright Springer Science+Business Media, LLC. 2012