En gruppe forskere har gennemgået amerikansk forskning og konkulderedet at

When focusing on studies with the highest caliber research designs, we found that inmates participating in correctional education programs were 28% less likely to recidivate when compared with inmates who did not participate in correctional education programs. 

https://link.springer.com/article/10.1007%2Fs11292-018-9334-6

Bozick, R., Steele, J., Davis, L. et al. Does providing inmates with education improve postrelease outcomes? A meta-analysis of correctional education programs in the United States. J Exp Criminol14, 389–428 (2018). https://doi.org/10.1007/s11292-018-9334-6