1. University of North Carolina at Chapel Hill; Department of Sociology; 155 Hamilton Hall CB #3210 Chapel HIll North Carolina USA 27510
2. University of Oxford; Centre for Evidence-Based Intervention, Department of Social Policy and Intervention; 32 Wellington Square Oxford Oxfordshire UK OX1 2ER
3. University of Michigan; Department of Psychology; 503 Church Street Ann Arbor Michigan USA 48109
4. Johns Hopkins University Bloomberg School of Public Health; Department of Epidemiology; 615 North Wolfe Street Baltimore Maryland USA 21205