Retraction

This article has been retracted [1] by the authors because they do not have ownership of the data presented, which was originally collected by the Laboratorio Management e Sanità of Scuola Superiore Sant’Anna. In addition, the data presented in this article has previously been used for a publication in the Italian journal “Mercati e Competitività” [2]. The authors apologise to the readers, the publisher and the authors of the Italian publication for any inconvenience caused.