The black-white education gap has been widely observed at many age levels. In a new working paper called "Race and College Success" (abstract; PDF), Peter Arcidiacono and Cory Koedel examine why blacks who are admitted to college are so much less likely than whites to graduate:
Conditional on enrollment, African American students are substantially less likely to graduate from 4-year public universities than white students.* Using administrative micro data from Missouri, we decompose the graduation gap between African Americans and whites into four factors: (1) racial differences in how students sort to universities, (2) racial differences in how students sort to initial majors, (3) racial differences in school quality prior to entry, and (4) racial differences in other observed pre-entry skills. Pre-entry skills explain 65 and 86 percent of the gap for women and men respectively. A small role is found for differential sorting into college, particularly for women, and this is driven by African Americans being disproportionately represented at urban schools and the schools at the very bottom of the quality distribution.
* "At around 40 percent, six-year graduation rates for African Americans are over twenty percentage points lower than for whites (DeAngelo et al., 2011, National Center for Education Statistics, 2012)."