1. Department of Statistical Sciences, Sapienza University of Rome, Rome, Italy.
2. Department of Political Sciences, University of Roma Tre, Rome, Italy.
3. Italian National Institute of Statistics (ISTAT), Rome, Italy.
4. Interdisciplinary Center for Research and Education on Population Change, University of Southern Denmark, Odense, Denmark.
5. Department of Public Health, University of Southern Denmark, Odense, Denmark.
6. Duke University Population Research Institute, Durham, NC, USA.
7. Max Planck Institute for Demographic Research, Rostock, Germany.
8. Department of Demography, University of California, Berkeley, CA, USA.