Association for Public Policy Analysis & Management

There is a substantial amount of research on the relationship between a student’s peers and their own academic achievement. However, there is less known about the relationship between a teacher’s peer quality and her own career trajectory. Existing research suggests that the quality of a teacher’s peers can impact both their own quality (Jackson & Bruehmann, 2009; Hanushek & Rivkin, 2005; Papay et. al, 2015) and mobility (Feng & Sass, 2008). This paper estimates the relationship between teacher peer quality and a teacher’s own quality and mobility, with a particular emphasis on the early portion of a teacher’s career, where the greatest amount of absolute skill growth occurs.

This paper uses student and teacher-level data from the Los Angeles Unified School District (LAUSD) from the years 2005-06 to 2015-16, including a total of 11,341 math and ELA teachers connected to their students. Measures of teacher peer quality include value-added estimates of their peer’s impact on student achievement as well as data from the Educator Development & Support for Teachers (EDST) program, an observation-based multiple measure teacher evaluation system (MMTES) in use in LAUSD since 2012-13. By tying student achievement and teacher mobility to specific measures of their peer teacher quality, we can more precisely estimate the relationship between particular aspects of teacher’s peer quality and their own quality and mobility.

To estimate the relationship between teacher peer quality and student achievement, a teacher-school fixed effects model predicting student achievement as a function of teacher quality and student and teacher characteristics is estimated. This analytic approach ensures that variation in teacher peer quality comes only from a teacher moving between grades within their school or from their peers moving out of their grade or school. Along with the inclusion of school by year fixed effects, this approach means that estimates will only be biased if high or low quality teachers are added to specific grades within a school contemporaneous with a shock that differentially affects that same grade and school. To estimate the relationship between teacher mobility and peer quality, a multinomial logistic regression predicts each teacher’s mobility outcome (i.e. stay in their school, switch schools within LAUSD, or leave LAUSD) as a function of peer quality and teacher and school-level characteristics.

Results suggest a weakly positive relationship between early-career teacher peer quality and a teacher’s own contribution to student achievement, although the significance of this relationship varies strongly based on the particular measure of peer quality used. In contrast, no consistent relationship is found between teacher peer quality and teacher mobility. Taken together, these findings suggest that a teacher’s peer quality is a potentially important and often overlooked contributor to their own performance, an important observation for the future development and evaluation of education policy.