Followup data included information on both official and self-reported delinquency and delinquency among siblings. Results indicate a significant rise in delinquency rates in the intervening years among both innercity and suburban youth. Factors most strongly associated with delinquency in both the initial and followup studies included economic deprivation (e.g., low family income, poor housing, low social class), parental criminality and sibling delinquency, poor parental supervision and childbearing behaviors, and poor academic performance (as evidenced by poor vocabulary, low IQ, and truancy). Of these factors, poor parental supervision and parenting were most important in facilitating official delinquency. 8 notes, 16 tables, and 27 references.