males and lower income students. Also, the effects of class composition in terms of gender and ability appear to be inverse …"We study how class size and class composition affect the academic and labor market performance of college students … random assignment of students to teaching classes. We find that a one standard deviation increase in class-size results in a …

increase the likelihood of earning a college degree by 1.6 percentage points and shift students towards high-earning fields …

for low income students and males. Estimates suggest that entering kindergarten early may have a detrimental effect on …