Proponents assert juvenile court sanctions and services are not just or effective responses to savvy juvenile offenders and believe criminal prosecution will ensure more proportionate punishment, provide more effective deterrence, and achieve greater incapacitation. The empirical evidence is too limited to be definitive but suggests most of these assertions are wrong. Expansive transfer policies send many minor and non-threatening juvenile offenders to the adult system, exacerbate racial disparities, and move adolescents with special needs into correctional systems that are not prepared to handle them. Transfer results in more severe penalties for some juvenile offenders, but there is no evidence it achieves either general or specific deterrent effects. There is credible evidence that prosecution and punishment in the adult system increase the likelihood of recidivism, thus offsetting incapacitative gains. Transfer also exposes young people to heightened vulnerability to a host of unfortunate experiences and outcomes. Additional research is recommended to assess the number and kinds of young people transferred to and processed through the adult system. 86 references, 39 footnotes, and 12 tables