“…When multivariate response variables are concerned, however, the univariate quantile regression method does not straightforwardly extend to higher dimensions since there is no ‘natural’ ordering in a p ‐dimensional space, for p > 1. As a consequence, the search for a satisfactory notion of multivariate quantile has led to a flourishing literature on this topic despite its definition is still a debatable issue (see Alfò et al, 2021; Chakraborty, 2003; Charlier et al, 2020; Chavas, 2018; Hallin et al, 2010; Koenker et al, 2017; Kong & Mizera, 2012; Merlo et al, 2021; Stolfi et al, 2018 and the references therein for relevant studies). Recently, Petrella and Raponi (2019) generalized the AL distribution inferential approach of the univariate quantile regression to a multivariate framework by using the multivariate asymmetric Laplace (MAL) distribution defined in Kotz et al (2012).…”