Evaluator: Bell, A. Georgia State University Department of Economics

Evaluation Methods:

The research study conducts a re-analysis of data collected from a 1991 randomized control trial involving 959 participants from eight BBBSA affiliates, evaluating the effects of BBBS mentoring on broad social and emotional outcomes 18 months after being matched with a mentor. Researchers employed an intent-to-treat analysis, with the treatment group comprising individuals matched with a mentor and the control group consisting of those placed on a waitlist. To supplement the randomized control analysis, the study employs an observational research design, incorporating a larger administrative dataset of approximately 9,000 youth applicants from the Boston affiliate, due to its extensive administrative records that date back unusually far. Researchers link youth from the original dataset and those from the Boston dataset to 2014 tax records to explore the effects of mentoring on the behavioral and economic outcomes of participants aged 20 to 30 years. The secondary study employs a treatment-on-the-treated analysis, comparing behavioral and economic outcomes of youth who were matched with a mentor, and those who applied but were never matched through BBBS. 

Evaluation Type: Experimental;Non-experimental

Summary of Outcomes:

This study finds significant benefits of participation in Big Brothers Big Sisters mentoring in adolescence and adulthood, including improved behavioral outcomes such as increased college attendance and higher earnings in young adulthood and throughout participants’ lifetimes. 

Re-analysis of the 1991 randomized control trial indicates that those assigned a mentor experienced greater short and long-term behavioral outcomes compared to those who were not assigned (control group), as evidenced by self-reports and matched tax records. The analysis revealed that young people in BBBS are 10 percentage points more likely to attend college by age 20 than the control group. Additionally, young people who were assigned a mentor through BBBS are 6 percentage points (16.2%) more likely to be married and 5 percentage points (16.1%) less likely to have had a teen birth. Mortality and incarceration outcomes were not statistically significant, but favored participants. 

For a deeper understanding of the impact of programming on future earnings, a supplementary observational research design was employed within a larger dataset. Findings corroborate behavioral outcomes from the RCT re-analysis and demonstrate considerable economic impacts on mentored youth. Compared to youth who were not matched with a BBBS mentor, matched youth were 9.3 percentage points more likely to attend college. When adding controls for parent income, year of birth, application year, and census tract, the point estimates for college attendance weaken, but remain statistically significant (7.1 percentage points more likely). The study also finds that between the ages of 20 and 25, matched youth earn nearly 20% more than unmatched youth, and have 17.4% more income, although the mean income for both groups in this age range is low. Combining economic findings from the original RCT and the observational analysis, matched youth are estimated to experience a 15% increase in earnings between the ages of 20 and 25. 

The study also finds variation in outcomes correlated with treatment intensity, revealing that those matched for the longest periods yield the most significant outcomes. For instance, each year of being matched with a mentor is associated with a 1.6 percentage point increase in college attendance, a 2.8% increase in individual income, and a 1.3 percentage point decrease in non-employment between the ages 20 and 25. 

Finally, given the estimated 15% boost in earnings experienced by matched youth, this figure is used to assess differences in cumulative lifetime earnings between the two groups. Using an age-income profile to predict future earnings, the study finds that participants are expected to earn $56,000 more by age 65, at present value, than non-participants.