We present a multiple spells-competing risks model of stopout, dropout, reenrollment, and graduation behavior. We find that students who experience an initial stopout are more likely to experience subsequent stopouts (occurrence dependence) and are less likely to graduate. We also find evidence of the impact of the length of an initial spell on the probability of subsequent events (lagged duration dependence). We simulate the impacts of race, family income, and high school performance on student behavior and show that there are often very large differences between unadjusted rates of student outcomes and adjusted rates. Differences in student performance often ascribed to race are shown to be the result of income, age at entry, and high school performance.