1Ph.D., Yale University, School of Public Health, New Haven, CT, USA 2Ph.D., University of Wisconsin-Madison, Department of Economics, Department of Population Health Sciences, and La Follette School of Public Affairs, Madison, WI, USA * Correspondence to: Jason Fletcher, Ph.D., YaleUniversity, School of Public Health, 60 College Street # 303, New Haven, CT06520, USA. Tel.: +1-203-785 5760 Fax: +1