Families have also experienced changes these years. More families consist of one-parent households or two working parents. consequently, children are likely to have less supervision at home than was common in the traditional family structure. This lack of parental supervision is thought to be an influence on juvenile crime rates. Other identifiable causes of offensive acts include frustration or failure in school, the increased availability of drugs and alcohol, and the growing incidence of child abuse and child neglect. All these conditions tend to increase the probability of a child committing a criminal act, although a direct causal relationship has not yet been established.