1. Graduate School of Arts and Sciences, Harvard University, Cambridge, MA 02115
2. Department of Sociology, University of North Carolina, Chapel Hill, NC 27599
3. Department of Medicine, Division of Geriatrics, University of California, Los Angeles, CA 90095
4. Andrus Gerontology Center, Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089
5. SurveyMeter, Yogyakarta 55281, Indonesia
6. Department of Economics, Duke University, Durham, NC 27708