1. Department of Health Promotion, Education and Behavior, Arnold School of Public Health University of South Carolina Columbia SC USA
2. Department of Tobacco Research, Center for Population Health Research National Institute of Public Health Cuernavaca Mexico
3. Department of Epidemiology and Biostatistics, Arnold School of Public Health University of South Carolina Columbia SC USA
4. Department of Economics Autonomous University of Baja California Sur La Paz Mexico
5. Evaluation and Surveys Research Center National Institute of Public Health Mexico City Mexico