This paper studies a natural experiment due to an unusual change in the college admission policy at a Chinese university, which brought a large number of low-score students into several academic departments in the university. Exploiting large variations in peer characteristics and strong interactions among peer groups, the analysis finds that…

In 1997, Chicago implemented a policy that required algebra for all ninth-grade students, eliminating all remedial coursework. This policy increased opportunities to take algebra for low-skill students who had previously enrolled in remedial math. However, little is known about how schools respond to the policy in terms of organizing math…