A Note on the Maximum Difference Between Schweizer and Wolff ’s σ and the Absolute Value of Spearman’s ρ

In this note we correct an error on the possible maximum difference between the (measure of dependence) Schweizer and Wolff’s σ and the absolute value of the (measure of concordance) Spearman’s ρ given in [8]. Moreover, we provide a possible value for that possible, leaving its proof as an open problem.