Effects of Housing Vouchers on the Long-Term Exposure to Neighborhood Opportunity among Low-Income Families: The Moving to Opportunity Experiment.

Tenant-based rental assistance has received much attention as a tool to ameliorate American poverty and income segregation. We examined whether a tenant-based voucher program improves long-term exposure to neighborhood opportunity overall and across multiple domains-social/economic, educational, and health/environmental-among low-income families with children. We used data from the Moving to Opportunity (MTO) experiment (1994-2010) with a 10- to 15-year follow-up period and used an innovative and multidimensional measure of neighborhood opportunities for children. Compared with controls in public housing, MTO voucher recipients experienced improvement in neighborhood opportunity overall and across domains during the entire study period, with a larger treatment effect for families in the MTO voucher group who received supplementary housing counseling, than the Section 8 voucher group. Our results also suggests that effects of housing vouchers on neighborhood opportunity may not be uniform across subgroups. Results from model-based recursive partitioning for neighborhood opportunity identified several potential effect modifiers for housing vouchers, including study sites, health and developmental problems of household members, and having vehicle access.

Do Alcohol Outlets Mediate the Effects of the Moving to Opportunity Experiment on Adolescent Excessive Drinking? A Secondary Analysis of a Randomized Controlled Trial.

Background: Housing mobility impacts adolescent alcohol use, and the neighborhood built environment may impact this relationship. Methods: Moving to Opportunity (MTO) was a multi-site, three-arm, household-level experiment. MTO randomly assigned one of three treatment arms (1994-1997) allowing families living in public housing to (1) receive a voucher to be redeemed any neighborhood (2) receive a voucher to be redeemed in a neighborhood with less than 10% poverty (3) remain in public housing (control). MTO decreased girls' alcohol use, but increased boys' alcohol use. Treatment groups were pooled because they are similar conceptually and statistically on our primary outcome. Among youth aged 12-19 in 2001-2002 (N = 2829), we estimated controlled direct effects mediation of MTO treatment effects on youth with housing vouchers (N = 1950) vs. controls (N = 879) on past 30-day number of drinks per day on days drank, using gender-stratified Poisson regression. Mediators were density of on- and off-premises alcohol outlets per square mile at the families' census tract of residence in 1997. Results: Treatment group youth were randomized to live in 1997 census tracts with lower off-premises, but higher on-premises, outlet density. MTO treatment (vs. controls) decreased drinking for girls via alcohol outlet density, but only at higher levels of outlet density. Treatment was 18% more beneficial when girls moved to high density neighborhoods, compared to controls who stayed living in public housing in high density neighborhoods. Conclusion: Additional social processes unmeasured in the current study may play an important role in the alcohol use and other health risks for girls.

Housing mobility protects against alcohol use for children with socioemotional health vulnerabilities: An experimental design.

PURPOSE: Neighborhood context may influence alcohol use, but effects may be heterogeneous, and prior evidence is threatened by confounding. We leveraged a housing voucher experiment to test whether housing vouchers' effects on alcohol use differed for families of children with and without socioemotional health or socioeconomic vulnerabilities. TRIAL DESIGN: In the Moving to Opportunity (MTO) study, low-income families in public housing in five US cities were randomized in 1994 to 1998 to receive one of three treatments: (1) a housing voucher redeemable in a low-poverty neighborhood plus housing counseling, (2) a housing voucher without locational restriction, or (3) no voucher (control). Alcohol use was assessed 10 to 15 years later (2008 to 2010) in youth ages 13 to 20, N = 4600, and their mothers, N = 3200. METHODS: Using intention-to-treat covariate-adjusted regression models, we interacted MTO treatment with baseline socioemotional health vulnerabilities, testing modifiers of treatment on alcohol use. RESULTS: We found treatment effect modification by socioemotional factors. For youth, MTO voucher treatment, compared with controls, reduced the odds of ever drinking alcohol if youth had behavior problems (OR = 0.26, 95% CI [0.09, 0.72]) or problems at school (OR = 0.46, [0.26, 0.82]). MTO low-poverty treatment (vs. controls) also reduced the number of drinks if their health required special medicine/equipment (OR = 0.50 [0.32, 0.80]). Yet treatment effects were nonsignificant among youth without socioemotional vulnerabilities. Among mothers of children with learning problems, MTO voucher treatment (vs. controls) reduced past-month drinking (OR = 0.69 [0.47, 0.99]), but was harmful otherwise (OR = 1.22 [0.99, 1.45]). CONCLUSIONS: For low-income adolescents with special needs/socioemotional problems, housing vouchers protect against alcohol use.

Does the Temporal Pattern of Moving to a Higher-Quality Neighborhood Across a 5-Year Period Predict Psychological Distress Among Adolescents? Results From a Federal Housing Experiment.

Using data from the Moving to Opportunity (MTO) experiment (1994-2002), this study examined how a multidimensional measure of neighborhood quality over time influenced adolescent psychological distress, using instrumental variable (IV) analysis. Neighborhood quality was operationalized with the independently validated 19-indicator Child Opportunity Index (COI), linked to MTO family addresses over 4-7 years. We examined whether being randomized to receive a housing subsidy (versus remaining in public housing) predicted neighborhood quality across time. Using IV analysis, we tested whether experimentally induced differences in COI across time predicted psychological distress on the Kessler Screening Scale for Psychological Distress (n = 2,829; mean ß = -0.04 points (standard deviation, 1.12)). The MTO voucher treatment improved neighborhood quality for children as compared with in-place controls. A 1-standard-deviation change in COI since baseline predicted a 0.32-point lower psychological distress score for girls (ß = -0.32, 95% confidence interval: -0.61, -0.03). Results were comparable but less precisely estimated when neighborhood quality was operationalized as simply average post-random-assignment COI (ß = -0.36, 95% confidence interval: -0.74, 0.02). Effect estimates based on a COI excluding poverty and on the most recent COI measure were slightly larger than other operationalizations of neighborhood quality. Improving a multidimensional measure of neighborhood quality led to reductions in low-income girls' psychological distress, and this was estimated with high internal validity using IV methods.

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

PURPOSE: The purpose of this study was to understand why a housing mobility experiment caused harmful effects on adolescent boys' risky behaviors. METHODS: 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). RESULTS: 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%. CONCLUSIONS: 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.

Do changes in neighborhood social context mediate the effects of the moving to opportunity experiment on adolescent mental health?

This study investigated whether changes in neighborhood context induced by neighborhood relocation mediated the impact of the Moving to Opportunity (MTO) housing voucher experiment on adolescent mental health. Mediators included participant-reported neighborhood safety, social control, disorder, and externally-collected neighborhood collective efficacy. For treatment group members, improvement in neighborhood disorder and drug activity partially explained MTO's beneficial effects on girls' distress. Improvement in neighborhood disorder, violent victimization, and informal social control helped counteract MTO's adverse effects on boys' behavioral problems, but not distress. Housing mobility policy targeting neighborhood improvements may improve mental health for adolescent girls, and mitigate harmful effects for boys.

The unequal distribution of sibling and parent deaths by race and its effect on attaining a college degree.

PURPOSE: Examine (1) the distribution of experiencing the death of a parent or sibling (family death) by race/ethnicity and (2) how a family death affects attaining a college degree. METHODS: Participants (n = 8984) were from National Longitudinal Survey of Youth 1997 aged 13-17 at baseline in 1997 and 29-32 in 2013. We examined the prevalence of family deaths by age group and race/ethnicity and used covariate-adjusted logistic regression to assess the relationship between a family death and college degree attainment. RESULTS: A total of 4.2% of white youth experienced a family death, as did 5.0% of Hispanics, 8.3% of Blacks, 9.1% of Asians, and 13.8% of American Indians (group test P < .001). A family death from ages 13-22 was associated with lower odds of obtaining a bachelor's degree by ages 29-32 (OR = 0.65, 95% CI = 0.50, 0.84), compared with no family death. The effect of a death was largest during college years (age 19-22) (OR = 0.57, 95% CI = 0.39, 0.82). CONCLUSIONS: Young people of color are more likely to have a sibling or parent die; and family death during college years is associated with reduced odds of obtaining a college degree. Racial disparities in mortality might affect social determinants of health of surviving relatives, and college policies are a potential intervention point.

Using Transportability to Understand Differences in Mediation Mechanisms Across Trial Sites of a Housing Voucher Experiment.

BACKGROUND: Randomized trials may have different effects in different settings. Moving to Opportunity (MTO), a housing experiment, is one such example. Previously, we examined the extent to which MTO's overall effects on adolescent substance use and mental health outcomes were transportable across the sites to disentangle the contributions of differences in population composition versus differences in contextual factors to site differences. However, to further understand reasons for different site effects, it may be beneficial to examine mediation mechanisms and the degree to which they too are transportable across sites. METHODS: We used longitudinal data from MTO youth. We examined mediators summarizing aspects of the school environment over the 10-15 year follow-up. Outcomes of past-year substance use, mental health, and risk behavior were assessed at the final timepoint when participants were 10-20 years old. We used doubly robust and efficient substitution estimators to estimate (1) indirect effects by MTO site and (2) transported indirect effects from one site to another. RESULTS: Differences in indirect effect estimates were most pronounced between Chicago and Los Angeles. Using transport estimators to account for differences in baseline covariates, likelihood of using the voucher to move, and mediator distributions partially to fully accounted for site differences in indirect effect estimates in 10 of the 12 pathways examined. CONCLUSIONS: Using transport estimators can provide an evidence-based approach for understanding the extent to which differences in compositional factors contribute to differences in indirect effect estimates across sites, and ultimately, to understanding why interventions may have different effects when applied to new populations.

Effects of a federal housing voucher experiment on adolescent binge drinking: a secondary analysis of a randomized controlled trial.

AIMS: To test how a housing voucher generating residential mobility to lower-poverty neighborhoods, compared with public housing controls, influenced adolescent binge drinking, and whether gender modified effects. DESIGN: A multi-site household-level three-arm randomized trial of a housing intervention executed 1994-98, evaluated 2001-02. SETTING: Five US cities: Baltimore, MD; Boston, MA; Chicago, IL; Los Angeles, CA; and New York, NY. PARTICIPANTS: A total of 3537 adolescents in 4248 low-income eligible families were randomized; 2829 adolescents were analyzed at the interim evaluation (1950 in treatment; 879 in the control group). Attrition bias was accounted for with a 3-in-10 oversampling of hard-to-reach participants (effective response rate: 89%). INTERVENTIONS: The Moving to Opportunity (MTO) trial randomized volunteer low-income families in public housing to receive (1) rental subsidies redeemable in neighborhoods with < 10% tract poverty plus housing counseling, (2) unrestricted Section 8 rental subsidies or (3) to remain in public housing. We pooled the subsidy ('treatment') groups because they were conceptually similar and there was no evidence of statistical differences between groups on binge drinking. MEASUREMENTS: Primary outcome: past month binge drinking (five or more drinks in one sitting). FINDINGS: Adolescent binge drinking prevalence was 3.9% for treatment and 3.2% for control. The intention-to-treat (ITT) main effect of subsidy treatment (versus control) on binge drinking was non-significant, but treatment effects were different for girls and boys (treatment-gender interaction P = 0.002). MTO treatment reduced girls' binge drinking [odds ratio (OR) = 0.48, 95% confidence interval (CI) = 0.24-0.96, P = 0.037], but increased boys' binge drinking (OR = 2.37, 95% CI = 1.13-4.97, P = 0.023), compared with controls. Results were similar for secondary alcohol outcomes. Instrumental variable (IV) results adjusting for treatment compliance were comparable with ITT, but larger. CONCLUSIONS: A housing subsidy treatment that enables low-income families to move from public to private housing appears to lessen girls' binge drinking but increases boys' binge drinking, compared with controls.

The price of admission: does moving to a low-poverty neighborhood increase discriminatory experiences and influence mental health?

PURPOSE: The Moving to Opportunity (MTO) study is typically interpreted as a trial of changes in neighborhood poverty. However, the program may have also increased exposure to housing discrimination. Few prior studies have tested whether interpersonal and institutional forms of discrimination may have offsetting effects on mental health, particularly using intervention designs. METHODS: We evaluated the effects of MTO, which randomized public housing residents in 5 cities to rental vouchers, or to in-place controls (N = 4248, 1997-2002), which generated variation on neighborhood poverty (% of residents in poverty) and encounters with housing discrimination. Using instrumental variable analysis (IV), we derived two-stage least squares IV estimates of effects of neighborhood poverty and housing discrimination on adult psychological distress and major depressive disorder (MDD). RESULTS: Randomization to voucher group vs. control simultaneously decreased neighborhood % poverty and increased exposure to housing discrimination. Higher neighborhood % poverty was associated with increased psychological distress [BIV = 0.36, 95% confidence interval (CI) 0.03, 0.69] and MDD (BIV = 0.12, 95% CI - 0.005, 0.25). Effects of housing discrimination on mental health were harmful, but imprecise (distress BIV = 1.58, 95% CI - 0.83, 3.99; MDD BIV = 0.57, 95% CI - 0.43, 1.56). Because neighborhood poverty and housing discrimination had offsetting effects, omitting either mechanism from the IV model substantially biased the estimated effect of the other towards the null. CONCLUSIONS: Neighborhood poverty mediated MTO treatment on adult mental health, suggesting that greater neighborhood poverty contributes to mental health problems. Yet housing discrimination-mental health findings were inconclusive. Effects of neighborhood poverty on health may be underestimated when failing to account for discrimination.

Mediation of Neighborhood Effects on Adolescent Substance Use by the School and Peer Environments.

BACKGROUND: Evidence suggests that aspects of the neighborhood environment may influence risk of problematic drug use among adolescents. Our objective was to examine mediating roles of aspects of the school and peer environments on the effect of receiving a Section 8 housing voucher and using it to move out of public housing on adolescent substance use outcomes. METHODS: We used data from the Moving to Opportunity (MTO) experiment that randomized receipt of a Section 8 housing voucher. Hypothesized mediators included school climate, safety, peer drug use, and participation in an after-school sport or club. We applied a doubly robust, semiparametric estimator to longitudinal MTO data to estimate stochastic direct and indirect effects of randomization on cigarette use, marijuana use, and problematic drug use. Stochastic direct and indirect effects differ from natural direct and indirect effects in that they do not require assuming no posttreatment confounder of the mediator-outcome relationship. Such an assumption would be at odds with any causal model that reflects an intervention affecting a mediator and outcome through adherence to treatment assignment. RESULTS: Having friends who use drugs and involvement in after-school sports or clubs partially mediated the effect of housing voucher receipt on adolescent substance use (e.g., stochastic indirect effect 0.45% [95% confidence interval: 0.12%, 0.79%] for having friends who use drugs and 0.04% [95% confidence interval: -0.02%, 0.10%] for involvement in after-school sports or clubs mediating the relationship between housing voucher receipt and marijuana use among boys). However, these mediating effects were small, contributing only fractions of a percent to the effect of voucher receipt on probability of substance use. No school environment variables were mediators. CONCLUSIONS: Measured school- and peer-environment variables played little role in mediating the effect of housing voucher receipt on subsequent adolescent substance use.

Modification of Housing Mobility Experimental Effects on Delinquency and Educational Problems: Middle Adolescence as a Sensitive Period.

Residential mobility is one documented stressor contributing to higher delinquency and worse educational outcomes. Sensitive period life course models suggest that certain developmental stages make individuals more susceptible to the effects of an exposure, like residential mobility, on outcomes. However, most prior research is observational, and has not examined heterogeneity across age or gender that may inform sensitive periods, even though it may have important implications for the etiology of adolescent development. Moreover, there are important translational implications for identifying the groups most vulnerable to residential mobility to inform how to buffer adverse effects of moving. In this study, low-income families were randomized to residential mobility out of public housing into lower poverty neighborhoods using a rental subsidy voucher ("experimental voucher condition"), and were compared to control families remaining in public housing. The sample was comprised of 2829 youth (51% female; 62% Non-Hispanic Black, 31% Hispanic, 7% other race). At baseline, youth ranged from 5 to 16 years old. This study hypothesized that random assignment to the housing voucher condition would generate harmful effects on delinquency and educational problems, compared to the control group, among boys who were older at baseline. The results confirmed this hypothesis: random assignment to the experimental voucher condition generating residential mobility caused higher delinquency among boys who were 13-16 years old at baseline, compared to same-age, in-place public housing controls. However, residential mobility did not affect delinquency among girls regardless of age, or among boys who were 5-12 years old at baseline. The pattern of results for educational problems was similar but weaker. Families with teenage boys are particularly vulnerable to residential transitions. Incorporating additional supports into housing programs may help low-income, urban families to successfully transition to lower poverty neighborhoods.

Composition or Context: Using Transportability to Understand Drivers of Site Differences in a Large-scale Housing Experiment.

BACKGROUND: The Moving To Opportunity (MTO) experiment manipulated neighborhood context by randomly assigning housing vouchers to volunteers living in public housing to use to move to lower poverty neighborhoods in five US cities. This random assignment overcomes confounding limitations that challenge other neighborhood studies. However, differences in MTO's effects across the five cities have been largely ignored. Such differences could be due to population composition (e.g., differences in the racial/ethnic distribution) or to context (e.g., differences in the economy). METHODS: Using a nonparametric omnibus test and a multiply robust, semiparametric estimator for transportability, we assessed the extent to which differences in individual-level compositional characteristics that may act as effect modifiers can account for differences in MTO's effects across sites. We examined MTO's effects on marijuana use, behavioral problems, major depressive disorder, and generalized anxiety disorder among black and Latino adolescent males, where housing voucher receipt was harmful for health in some sites but beneficial in others. RESULTS: Comparing point estimates, differences in composition partially explained site differences in MTO effects on marijuana use and behavioral problems but did not explain site differences for major depressive disorder or generalized anxiety disorder. CONCLUSIONS: Our findings provide quantitative, rigorous evidence for the importance of context or unmeasured individual-level compositional variables in modifying MTO's effects.

Housing mobility and adolescent mental health: The role of substance use, social networks, and family mental health in the Moving to Opportunity Study.

The Moving to Opportunity (MTO) experiment was a housing mobility program begun in the mid-nineties that relocated volunteer low income families from public housing to rental units in higher opportunity neighborhoods in 5 US cities, using the Section 8 affordable housing voucher program. Compared to the control group who stayed behind in public housing, the MTO voucher group exhibited a harmful main effect for boys' mental health, and a beneficial main effect for girls' mental health. But no studies have examined how this social experiment caused these puzzling, opposite gender effects. The present study tests potential mediating mechanisms of the MTO voucher experiment on adolescent mental health (n=2829, aged 12-19 in 2001-2002). Using Inverse Odds Ratio Weighting causal mediation, we tested whether adolescent substance use comorbidity, social networks, or family mental health acted as potential mediators. Our results document that comorbid substance use (e.g. past 30 day alcohol use, cigarette use, and number of substances used) significantly partially mediated the effect of MTO on boys' behavior problems, resulting in -13% to -18% percent change in the total effect. The social connectedness domain was a marginally significant mediator for boys' psychological distress. Yet no tested variables mediated MTO's beneficial effects on girls' psychological distress. Confounding sensitivity analyses suggest that the indirect effect of substance use for mediating boys' behavior problems was robust, but social connectedness for mediating boys' psychological distress was not robust. Understanding how housing mobility policies achieve their effects may inform etiology of neighborhoods as upstream causes of health, and inform enhancement of future affordable housing programs.

The effects of a housing mobility experiment on participants' residential environments.

We used the Moving to Opportunity (MTO) housing experiment to inform how housing choice vouchers and housing mobility policies can assist families living in high-poverty areas to make opportunity moves to higher quality neighborhoods, across a wide range of neighborhood attributes. We compared the neighborhood attainment of the three randomly-assigned MTO treatment groups (Low Poverty voucher, Section 8 voucher, Control group) at 1997 and 2002 locations (4-7 years after baseline), by using survey reports, and by linking residential histories to numerous different administrative and population-based datasets. Compared to controls, families in Low-Poverty and Section 8 groups experienced substantial improvements in neighborhood conditions across diverse measures, including economic conditions, social systems (e.g., collective efficacy), physical features of the environment (e.g., tree cover) and health outcomes. The Low-poverty voucher group moreover achieved better neighborhood attainment compared to Section 8. Treatment effects were largest for New York and Los Angeles. We discuss the implications of our findings for expanding affordable housing policy.

Adolescence Is a Sensitive Period for Housing Mobility to Influence Risky Behaviors: An Experimental Design.

PURPOSE: Test whether neighborhood mobility effects on adolescent risky behaviors varies at different developmental ages and gender. METHODS: The Moving to Opportunity (MTO) study randomly assigned volunteer families (1994-1997) to receive a Section 8 voucher to move to lower poverty neighborhoods versus a public housing control group. We tested three-way treatment, gender, and age-at-randomization interactions using intent-to-treat linear regression predicting a risky behavior index (RBI; measured in 2002, N = 2,829), defined as the fraction of 10 behaviors the youth reported (six measuring risky substance use [RSU], four measuring risky sexual behavior), and the RSU and risky sexual behavior subscales. RESULTS: The treatment main effect on RBI was nonsignificant for girls (B = -.01, 95% confidence interval -.024 to .014) and harmful for boys (B = .03, 95% confidence interval .009 to .059; treatment-gender interaction p = .01). The treatment, gender, and age interaction was significant for RBI (p = .02) and RSU (p ≤ .001). Treatment boys 10 years or older at randomization were more likely (p < .05) than controls to exhibit RBI and RSU, whereas there was no effect of treatment for boys <10 years. There were no treatment control differences by age for girls' RBI, but girls 9+ years were less likely than girls ≤8 years to exhibit RSU (p < .05). CONCLUSIONS: Moving families of boys aged 10 years or older with rental vouchers may have adverse consequences on risky behaviors but may be beneficial for girls' substance use. Developmental windows are different by gender for the effects of improving neighborhood contexts on adolescent risky behavior.

Heterogeneous Effects of Housing Vouchers on the Mental Health of US Adolescents.

OBJECTIVES: To assess the mental health effects on adolescents of low-income families residing in high-poverty public housing who received housing vouchers to assist relocation. METHODS: We defined treatment effects to compare 2829 adolescents aged 12 to 19 years in families offered housing vouchers versus those living in public housing in the Moving to Opportunity experiment (1994-1997; Boston, MA; Baltimore, MD; Chicago, IL; Los Angeles, CA; New York, NY). We employed model-based recursive partitioning to identify subgroups with heterogeneous treatment effects on psychological distress and behavior problems measured in 2002. We tested 35 potential baseline treatment modifiers. RESULTS: For psychological distress, Chicago participants experienced null treatment effects. Outside Chicago, boys experienced detrimental effects, whereas girls experienced beneficial effects. Behavior problems effects were null for adolescents who were aged 10 years or younger at baseline. For adolescents who were older than 10 years at baseline, violent crime victimization, unmarried parents, and unsafe neighborhoods increased adverse treatment effects. Adolescents who were older than 10 years at baseline without learning problems or violent crime victimization, and whose parents moved for better schools, experienced beneficial effects. CONCLUSIONS: Health effects of housing vouchers varied across subgroups. Supplemental services may be necessary for vulnerable subgroups for whom housing vouchers alone may not be beneficial.

Does Mother Know Best? Treatment Adherence as a Function of Anticipated Treatment Benefit.

BACKGROUND: We describe bias resulting from individualized treatment selection, which occurs when treatment has heterogeneous effects and individuals selectively choose treatments of greatest benefit to themselves. This pernicious bias may confound estimates from observational studies and lead to important misinterpretation of intent-to-treat analyses of randomized trials. Despite the potentially serious threat to inferences, individualized treatment selection has rarely been formally described or assessed. METHODS: The Moving To Opportunity trial randomly assigned subsidized rental vouchers to low-income families in high-poverty public housing. We assessed the Kessler-6 psychological distress and Behavior Problems Index outcomes for 2,829 adolescents 4-7 years after randomization. Among families randomly assigned to receive vouchers, we estimated probability of moving (treatment), predicted by prerandomization characteristics (c statistic = 0.63). We categorized families into tertiles of this estimated probability of moving, and compared instrumental variable effect estimates for moving on behavior problems index and Kessler-6 across tertiles. RESULTS: Instrumental variable estimated effects of moving on behavioral problems index were most adverse for boys least likely to move (b = 0.93; 95% confidence interval: 0.33, 1.53) compared with boys most likely to move (b = 0.14; 95% confidence interval: -0.15, 0.44; P = 0.02 for treatment × tertile interaction). Effects on Kessler-6 were more beneficial for girls least likely to move compared with girls most likely to move (-0.62 vs. 0.02; interaction; P = 0.03). CONCLUSIONS: Evidence of individualized treatment selection differed by child gender and outcome and should be evaluated in randomized trial reports, especially when heterogeneous treatment effects are likely and nonadherence is common.