Events and Meetings of Italian Statistical Society, Statistics and Demography: the Legacy of Corrado Gini

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Gini heterogeneity index for detecting uncertainty in ordinal data surveys
Stefania Capecchi, Maria Iannario

Last modified: 2015-09-05


In sample surveys where people are asked to give responses to items by means of ordinal scales it is common to register an inherent indecision generated by both objective and subjective causes. Thus, an effective statistical analysis should take this component into account to avoid bias in estimation, interpretation and prediction. In this paper, we show how the heterogeneity index proposed by Gini and its variants are effective measures to detect such an uncertainty. In addition the relationships of heterogeneity Gini's index with the parameter of a peculiar mixture model are discussed and exploited as a tool for exploratory selection of covariates. Then, a real case study is considered to check the effectiveness of these measures for finite sample size. Some concluding remarks end the paper.

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