– Assignment to a small class increases students’ probability of attending college by 2.7 percentage points, with effects more than twice as large among black students. Among students enrolled in the poorest third of schools, the effect is 7.3 percentage points.

– Smaller classes increased the likelihood of earning a college degree by 1.6 percentage points and shifted students toward high-earning fields such as STEM (science, technology, engineering, and mathematics), business, and economics.

– The authors also found that test-score effects at the time of the experiment were an excellent predictor of long-term improvements in postsecondary outcomes.

– Black and female students tended to enroll in higher proportions in for-profit colleges.

– The black-white gap in college entrance is about half as large in small classes (7.7 percentage points) as it is in regular classes (12.4 percentage points). The drastic reduction in the race gap in college attendance is driven by females, for whom the race gap virtually disappears in small classes.

– Assignment to a small class increased the likelihood of students entering college on time by 2.4 percentage points. Among those students enrolled in the poorest third of schools, the effect was 4.7 points.

– Assignment to a small class increases the likelihood of students completing a college degree by 1.6 percentage points.

– While 1.9 percent of the students in normal classes earned a degree in a STEM field, the rate was 2.4 percent for students that were in smaller classes.

– Enrollment effects are largest among black students, students from low-income families, and students from high-poverty schools, which indicates that class-size reductions during early childhood can help to close income and racial gaps in postsecondary attainment.

* Class size and its impacts on STEM enrollment