Can Early Intervention have a Sustained Effect on Human Capital?

Many early intervention studies experience a dissolution of treatment effects in the aftermath of the intervention. Using a randomized trial, this paper examines the impact of Preparing for Life, a pregnancy to age five home visiting and parenting program, on outcomes in middle childhood. I find significant treatment effects on cognitive skills (0.55SD) and school achievement tests (0.30-0.54SD) at age nine. There is no impact on socio-emotional skills and there is little evidence of treatment heterogeneity by gender, birth order, or distribution of ability. The effects are mainly driven by improvements in early parental beliefs.