The Gini Concentration Index for the Study of Survival

This chapter examines some developments that have occurred mostly over the past 20 years in the use of the Gini concentration index to study survival distributions. Most research on the Gini index estimation has focused on completely observed data. The Stata package Giniinc allows one to estimate the Gini concentration index under several conditions, both in the parametric and nonparametric setting. Also, in the nonparametric setting, a restricted version of the Gini concentration index has been introduced and exploited to construct a test for differences in survival distributions. The chapter reviews the contributions of the Gini concentration index to the study of survival distributions in demography for human and nonhuman populations. Indeed, considerable interest has recently emerged in the study of the concentration of lifespans within nonhuman populations. C. Gigliarano et al. propose to model the joint behavior of expected length of life and lifespan concentration through the parametric family of log-scale-location survival models.