Students who repeat a grade prior to high school have a higher risk of dropping out of high school than do students who are continuously promoted. This study tested whether standard theories of dropout--including the participation-identification model and the social capital model--explain this link. Although the presence of variables, including academic achievement and disciplinary problems, reduces the higher probability of retained students dropping out, existing models of dropping out do not adequately explain the markedly higher probability of dropping out for retained students. Regression decomposition reveals differences between promoted and retained students in the importance of resources and illustrates that various resources hold different levels of importance for white, black, and Latino students. (Contains 7 tables and 15 notes.)