“…Previous research indicates that social influences are important in shaping the health behavior of teenagers, including alcohol consumption (Kremer and Levy, 2008), smoking (Powell et al, 2005;Gaviria and Raphael, 2001), substance abuse (Lundborg, 2006;Clark and Loheac, 2007) and sexual initiation (Fletcher, 2007). There is also evidence on the importance of network effects in facilitating participation in welfare programs (Bertrand et al, 2000), utilization of health services (Deri, 2005) as well as in retirement and saving decisions (Duflo andSaez, 2002, 2003;Brown and Laschever, 2011). Most related to our context is the finding from the Health and Retirement Study that social interactions are an important determinant of the health insurance choices of the elderly (Beiseitov et al, 2004).…”