The gini-simpson index of diversity: estimation in the stratified sampling

In previous papers the problem of estimating the Gini-Simpson index of diversity for large populations has been considered by using random samplings with and without replacement, Nevertheless, the populations to which this estimation is usually applied (e.g., anthropoiogicai, ecological, linguistic and sociological populations) often arise naturally stratified. In this paper we first construct unbiased estimators of the Gini-Simpson index from a sample drawn according to a stratified sampling with proportional allocation and independently in different strata. Then, we determine the standard error of such estimators. The advantages of the stratification in estimating diversity are later confirmed by means of a practical example. We finally suggest complementary studies that could be additionally developed.