Gender Diversity Index. Measuring persistence research

Abstract

This paper deals with the analysis of the Gender Diversity Index (GDI), which is an Index developed by Solactive AG and is calculated and distributed by this provider. The index tracks the performance of developed world companies that are successfully working towards gender diversity as part of their CSR (Corporate Social Responsibility) strategy, and we measure its degree of persistence by using fractional integration or I(d) techniques. Using daily data from 8 December 2010 until 16 December 2020, the results indicate that the series is highly persistent with an order of integration lower than, though very close to 1. However, an interesting result is obtained by estimating d recursively across subsamples. The differencing parameter moves around 0.92 until 23 March 2020, with the series displaying a very small degree of mean reversion behaviour until that date. After that period, however, we observe an increase in the estimate of d, which stabilizes around 0.97 after 5 May 2020, though now the series presents evidence of a lack of mean reversion, with the shock having a permanent effect on the series. Thus, it seems that the sanitary crisis due to Covid-19 has had a clear effect in the degree of persistence of the GDI data.