1. Centre for Ageing Research and Education, Duke-NUS Medical School, Singapore, Singapore;
2. Department of Sociology, University of Michigan, Ann Arbor, MI, USA;
3. Population Studies Center, University of Michigan, Ann Arbor, MI, USA;
4. Sociology Programme, School of Social Sciences, Nanyang Technological University, Singapore, Singapore;
5. Department of Sociology, National University of Singapore, Singapore, Singapore