Students who are behind in grade for their age are likely to have repeated at least one grade. Therefore, age for grade is commonly used as a proxy in research for grade repetition. A number of studies demonstrate a relationship between repeating a grade and dropping out of high school. Jimerson, Carlson, Rotert, Egeland, and Sroufe (1997) found that repeating a grade is a predictor of dropping out of high school. McNeal (1995) found that students who were older than average were nearly twice as likely to dropout than their younger peers. Leventhal, Graber, and Brooks-Gunn (2001), in a sample of African American urban adolescents, found that adolescents who had repeated a grade were three times more likely to have dropped out of high school than those who never repeated a grade.

Repeating a grade in school or being behind in grade for age also predicts decreased likelihood of attending college. Borus and Carpenter (1984) found that high school seniors who were two or more years behind modal grade were less likely to attend college than those who were not behind in grade for age. Leventhal, Graber, and Brooks-Gunn (2001), in a sample of African American urban adolescents, found that adolescents who had repeated a grade during grades 1-6 were less likely to attend college. Zaff, et al. (2001) replicated these findings in an analysis of national data with their finding that students who had repeated a grade prior to the eighth grade were less likely to attend college than those who had not. All these studies controlled for background factors.