Educators raise concerns about what happens to students when they are exposed to new or new-to-school teachers. However, even when teachers remain in the same school they can switch roles by moving grades and/or subjects. We use panel data from New York City to compare four ways in which teachers are new to assignment: new to teaching, new to…

In practice, teacher turnover appears to have negative effects on school quality as measured by student performance. However, some simulations suggest that turnover can instead have large, positive effects under a policy regime in which low-performing teachers can be accurately identified and replaced with more effective teachers. This study…

This paper describes teacher tenure reforms first enacted by the New York City Department of Education (NYCDOE) during the 2009-10 academic year (AY) and the changes in the district's teacher workforce following the reforms. We show that the reforms dramatically changed the proportion of eligible teachers receiving tenure, as well as the career…

Teachers in the United States are compensated largely on the basis of fixed schedules that reward experience and credentials. However, there is a growing interest in whether performance-based incentives based on rigorous teacher evaluations can improve teacher retention and performance. The evidence available to date has been mixed at best. This…

Teachers in the United States are compensated largely on the basis of fixed schedules that reward experience and credentials. However, there is a growing interest in whether performance-based incentives based on rigorous teacher evaluations can improve teacher retention and performance. The evidence available to date has been mixed at best. This…

Teachers matter--and some matter more than others. That recognition has driven a tidal wave of controversial policy reforms over the past decade, rooted in new evaluation systems that link teachers' ratings and, in some cases, their pay and advancement to evidence of classroom practice and student learning. Two out of three U.S. states overhauled…

Educators raise concerns about what happens to students when they are exposed to new teachers or teachers who are new to a school. These teachers face the challenge of preparing a year's worth of new material, perhaps in an unfamiliar work environment. However, even when teachers remain in the same school they can switch jobs--teaching either a…

Researchers and policymakers often assume that teacher turnover harms student achievement, though recent studies suggest this may not be the case. Using a unique identification strategy that employs school-by-grade level turnover and two classes of fixed-effects models, this study estimates the effects of teacher turnover on over 850,000 New York…

Researchers and policymakers often assume that teacher turnover harms student achievement, but recent evidence calls into question this assumption. Using a unique identification strategy that employs grade-level turnover and two classes of fixed-effects models, this study estimates the effects of teacher turnover on over 600,000 New York City 4th…

Many large urban school districts are rethinking their personnel management strategies, often giving increased control to schools in the hiring of teachers, reducing, for example, the importance of seniority. If school hiring authorities are able to make good decisions about whom to hire, these reforms have the potential to benefit schools and…

This paper analyzes attrition patterns among teachers in New York City public elementary and middle schools and explores whether teachers who transfer among schools, or leave teaching entirely, are more or less effective than those who remain. We find that the first-year teachers who are less effective in improving student math scores have higher…

Almost a quarter of entering public-school teachers leave teaching within their first three years. High attrition would be particularly problematic if those leaving were the more able teachers. The goal of this paper is estimate the extent to which there is differential attrition based on teachers' value-added to student achievement. Using data…