The quality of the college is apparently really important to determining its graduation rate. According to an article by Eric Hoover at the Chronicle of Higher Education:
Joshua S. Goodman, an assistant professor of public policy, and Sarah Cohodes, a Ph.D. student, analyzed the educational outcomes of students who enrolled in Massachusetts public colleges through a scholarship program that waives tuition for students with test scores above specific thresholds. In other words, students who are qualified to attend private or out-of-state colleges of “higher quality,” as defined by measures such as on-time graduation rates and selectivity. The researchers compared the outcomes of scholarship recipients to those of similar students with test scores just below the thresholds for eligibility.
Although the scholarship program has succeeded in keeping more high-achieving students in Massachusetts, it did not help them graduate on time, the researchers conclude in a working paper. “Choosing a lower-quality college significantly lowers on-time completion rates, a result driven by high-skilled students who would otherwise have attended higher-quality colleges,” they write. “For the marginal student, enrolling at an in-state public college lowered the probability of graduating on time by more than 40 percent.”
This is important, because it indications that, in contrast to what many colleges with low graduation rates say, in fact the graduation rate of an institution is not entirely determined by the student body. A lot of the success toward graduation on time has to do with the actual program.
That being said, “quality” is a little vague here. Students are basically attending lower “quality” colleges if their grades and test score indicate they could be admitted to more selective schools. All of this, however, has nothing to do with what actually occurs in the school itself. The mere fact that the school is slightly more selective doesn’t necessarily indicate that it provides a superior education.