Section I discusses the countries' most basic decision regarding the management of juvenile problem behavior, i.e., whether a separate youth justice system is necessary to ensure that juveniles are processed and managed under policies appropriate to their age-related maturity. Although some of the countries have a juvenile justice system distinctive and separate from the adult juvenile justice system, other countries process juveniles in the adult court system, but under distinctive age-related policies that are less punitive than for adult offenders. Section II considers the complexity of mandated age limits that specify the minimum age at which harmful behaviors are treated as crimes, as well as the age beyond which a person is processed under the policies of the adult system rather than the juvenile system. Section III discusses the pros and cons of the relatively recent policy whereby a youth whose age permits processing as a juvenile is transferred to the adult system due to the severity of the crime charged. Section IV focuses on how various jurisdictions have reconciled the tension between welfare principles for addressing the problem behaviors of children and youth instead of applying the criminal law and associated punishments. The concluding section notes the contrast between the written laws that set policies for managing the problem behaviors of children and youth and how the policies operate in practice. 5 references