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. I...

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 November of 2007, the New York City Department of Education assigned each elementary and middle school a letter grade (A to F) as part of a new accountability system. Grades were based on continuous numeric scores derived from levels and changes in student achievement and other school...