"Mentoring has become an extremely popular policy for improving the retention and performance of new teachers, but we know little about its effects on teacher and student outcomes. I study the impact of mentoring in New York City, which adopted a nationally recognized mentoring program in 2004....

The gap between the qualifications of New York City teachers in high-poverty schools and low-poverty schools has narrowed substantially since 2000. Most of this gap-narrowing resulted from changes in the characteristics of newly hired teachers, and largely has been driven by the virtual...

In this paper, we show that the design and decentralized, school-based scoring of New York's high school exit exams - the Regents Examinations - led to the systematic manipulation of test sores just below important proficiency cutoffs. Our estimates suggest that teachers inflate approximately 40...