NBER Publications by Michele Pellizzari

We study how class size and class composition affect the academic and labor market performance of college students, two crucial policy questions given the secular increase in college enrollment. Our identification strategy relies on the random assignment of students to teaching classes. We find that a one standard deviation increase in class-size results in a 0.1 standard deviation deterioration of the average grade. Further, the effect is heterogeneous as it is stronger for males and lower income students. Also, the effects of class composition in terms of gender and ability appear to be inverse U-shaped. Finally, a reduction of 20 students (one standard deviation) in one's class size has a positive effect on monthly wages of about 80 Euros (115 USD) or 6% over the average.

In this paper we investigate whether peers' behavior influences the choice of college major, thus contributing to the mismatch of skills in the labor market. Using a newly constructed dataset, we are able to identify the endogenous effect of peers on such decisions through a novel identification strategy that solves the common econometric problems of studies of social interactions. Results show that, indeed, one is more likely to choose a major when many of her peers make the same choice. We also provide evidence on skills mismatch in terms of entry wages and occupation. We find that peers can divert students from majors in which they have a relative ability advantage, with adverse consequences on academic performance, entry wages and job satisfaction.