1. Department of Sociology/ICS, University of Groningen, Grote Rozenstraat 31, 9712 TG Groningen, The Netherlands
2. Population and Health Program, East-West Center, 1601 East-West Rd, Honolulu, HI 96848, USA
3. Carolina Population Center, University of North Carolina, CB#8120, Chapel Hill, NC 27514, USA
4. Australian Demographic and Social Research Institute, The Australian National University, Coombs Building (#9), Canberra ACT 0200, Australia
5. Department of Public Health, Erasmus UC, University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands