1. Department of Sociology, University of Michigan, LSA Building, 500 S. State Street, Ann Arbor, MI 48109-1382, USA
2. Bixby Center for Global Reproductive Health, University of California–San Francisco, 3333 California Street, Suite 265, San Francisco, CA 94118, USA
3. Institute for Social Research, University of Michigan, 426 Thompson St., Ann Arbor, MI 48104-2321, USA