1 Department of Demography, University of California, Berkeley, CA, USA, French Institute for Demographic Studies, Paris, France, magali@demog.berkeley.edu.
2 Department of Demography, University of California, Berkeley, CA, USA, Population Division, United Nations, Department of Economic and Social Affairs, New York, NY, USA.
3 Max Planck Institute for Demographic Research, Rostock, Germany, New Economic School, Moscow, Russia and.
4 Georgetown University, Washington, DC, USA.
5 Max Planck Institute for Demographic Research, Rostock, Germany.
6 Department of Demography, University of California, Berkeley, CA, USA.