[1] Sapienza Univ Rome, Dept Stat Sci, Piazzale Aldo Moro 5, I-00185 Rome, Italy
[2] Univ Parma, Dept Econ & Management, Parma, Italy
[3] Ulm Univ, Inst Med Syst Biol, Ulm, Germany
[4] Rikkyo Univ, Tokyo, Japan
[5] TU Dortmund Univ, Fac Stat, Dortmund, Germany