Do peer social relationships mediate the harmful effects of a housing mobility experiment on boys' risky behaviors?

The purpose of this study was to understand why a housing mobility experiment caused harmful effects on adolescent boys' risky behaviors. Moving to Opportunity (MTO) (1994–2010) randomly assigned volunteer families to a treatment group receiving a Section 8 rental voucher or a public housing control group. Our outcome was a global risky behavior index (RBI; measured in 2002, n = 750 boys) measuring the fraction of 10 items the youth engaged in, 6 measuring past 30-day substance use and 4 measuring recent risky sexual behavior. Potential mediators (measured in 2002) included peer social relationships (e.g., peer drug use, peer gang membership). The voucher treatment main effect on boys' RBI was harmful (B (SE) = 0.05 (0.02), 95% CI 0.01, 0.08), and treatment marginally increased having friends who used drugs compared to controls (B (SE) = 0.67 (0.23), 95% CI 0.22, 1.12). Having friends who used drugs marginally mediated the MTO treatment effect on RBI (indirect effect: B (SE) = 0.02(.01), 95% CI −0.002, 0.04), reducing the total treatment effect by 39%. Incorporating additional supports into housing voucher programs may help support teenage boys who experience disruptions to their social networks, to buffer potential adverse consequences of residential mobility.