A method for the comparative analysis of concentration of author productivity, giving consideration to the effect of sample size dependency of statistical measures

In this article, we propose a method for the comparative analysis of concentration in author productivity distributions. We define the notion of concentration on the basis of two viewpoints (absolute and relative concentration) and select G (Gini's index) and V (the number of authors) as suitable measures for these two viewpoints. We then discuss the statistical peculiarity of author productivity data (i.e., most of the statistical measures change systematically according to changes in the sample size) and we explain our method using developmental profiles, which takes into account the sample size dependency of statistical measures. Finally, by applying it to actual data, we demonstrate the usefulness of the proposed method.