**3.2 Method**

Analyses begin with significance tests to assess group-level differences in means for each measure of psychosocial development at Wave 1 and Wave 3. Next, the effects of confinement on psychosocial development in young adulthood are measured using standard regression models. Here, a lagged dependent variable is included to account for any differences in the baseline (Wave 1) measure of psychosocial development. The lagged variable model takes the following form: *Y XY t t tt* =+ + + ββ β ε1 2 31<sup>−</sup> , a standard regression equation with the inclusion of the

β3 1 *Yt*− term representing the baseline measure of the dependent variables (in this

case, the Wave 1 measure of psychosocial development). The model isolates the effect of confinement on development by minimizing any stable within-person or unmeasured elements psychosocial development.

Finally, to assess juvenile confinement effects and psychosocial development affect attainment in early adulthood, we use logistic regression models for each outcome measures first assess the effect of confinement on our attainment measures (net of controls) and second include Wave 3 psychosocial development (the more proximal measure) to determine whether and how psychosocial development diminishes any direct effect of juvenile confinement on young adult attainment.
