Discussion of “The class of CUB models: statistical foundations, inferential issues and empirical evidence”

We focus on on the multivariate extensions of CUB/GEM models. The interest of rating surveys is rarely focused on a single item or on a single aspect of an item. Respondents are often requested to express their opinion on different aspects of an issue and in such cases it is not negligible the roleof the interdependence of the answers of the same individual. With this aim in mind, we comment some existing classes of multivariate CUB models and present the advantages of a recent proposal.