1. Institut National de la Santé et de la Recherche Médical, Department of Epidemiology, Demography, and Social Sciences, Le Kremlin-Bicetre, France.
2. University of Massachusetts Medical School, Worcester, Massachusetts.
3. University Paris-Sud, Faculté de Médecine, Le Kremlin-Bicêtre, France.
4. INED, National Institute for Demographic Studies, Paris, France.
5. Office of Population Research, Princeton University, Princeton, New Jersey.
6. The Hull York Medical School, Hull, U.K.