A study, growing out of human capital theory, examined the economic consequences of dropping out of high school. Effect of schooling over time on labor market success (hourly pay rate, occupational prestige, and employment incidence and duration) was measured. Data on young men and women was obtained from the National Longitudinal Surveys of Labor Market Experience and personal interviews. The study universe consisted of respondents who left school between 1958-70 (males) and 1960-72 (females), completed nine-to-twelve years of schooling, and were not enrolled at the time of the survey. A three-equation recursive model was used to determine schooling contribution to success measures. Findings demonstrated substantial labor market benefits for all groups during the first decade of labor market experience. Earnings differences between graduates and dropouts were not pronounced immediately upon leaving school, but became significant over time. Graduates' age-earnings profiles were steeper than those of dropouts. The difference in occupational status between black graduates and dropouts shrank over time. All graduates, except black females, enjoyed greater immunity to unemployment than dropouts. In employment duration the advantage of black males and black and white females deteriorated over time; little difference was demonstrated between white male graduates and dropouts. (CSS)