This report by the Council of Economic Advisers analyzes key trends in teen behavior, and investigates the role of parents' involvement in their teenagers' lives. The report uses data from the National Longitudinal Study of Adolescent Health, a study of a nationally representative sample of seventh through twelfth graders, to examine the relationship between various teen behavioral outcomes and two measures of parental involvement: regularly eating dinner with the teen and perceived parent-child closeness. The report outlines significant opportunities and challenges for adolescents in the 21st century and demonstrates that teens are more likely to maximize opportunities and avoid risks when parents are involved in their lives. The report indicates that teenagers today live far healthier, more prosperous, and promising lives than ever before. Education levels have been improving across the board. College attendance rates have been increasing over the past decade, but income, race, and ethnicity still play a role. School-based teen participation in community service has increased. Despite increasing prosperity, teens are at high risk for poor nutrition. Rates of teen homicide and suicide remain high. Teen birth and pregnancy rates are steadily declining. The incidence of youth smoking rose during the 1990s. The report highlights findings from the longitudinal study indicating that parental involvement was a major influence in helping teens avoid risks while increasing educational achievement and expected attainment. Data tables are appended. (KB)