We use a Massachusetts merit aid program to provide the first clear causal evidence on the impact of college quality on students’ postsecondary enrollment decisions and rates of degree completion, where college quality is defined by a variety of measures including on-time graduation rates. High school students with test scores above multiple thresholds were granted tuition waivers at in-state public colleges of lower quality than the average alternative available to such students. A binding score regression discontinuity design comparing students just above and below these thresholds yields two main findings. First, students are remarkably willing to forego college quality for relatively small amounts of money. Second, choosing a lower quality college significantly lowers on-time completion rates, a result driven by highskilled students who would otherwise have attended higher quality colleges. For the marginal student, enrolling at an in-state public college lowered the probability of graduating on time by more than 40%. The low completion rates of scholarship users imply the program had little impact on the in-state production of college degrees. More broadly, these results suggest that the critically important task of improving college quality requires steps beyond merely changing the composition of the student body.