This study proposes a wavelet procedure for estimating partial correlation coefficients between stock market returns over different time scales. The estimated partial correlations are subsequently used in a cluster analysis to identify, for each time scale, groups of stocks that exhibit distinct...

The significance of the pharmaceutical and commercial sectors in the national economy has noticeably intensified, as a result of the COVID-19 pandemic. The main objective of this study was to gain a better insight into the main management characteristics of the actors in the sector. It was...