Teacher Layoffs:  An Empirical Illustration of Seniority v. Measures of Effectiveness.  July 2010.  Donald Boyd, Hamilton Lankford, Susanna Loeb, and James Wyckoff.

Today, the financial imbalance in many school districts is so large that there is no alternative to teacher layoffs.  In nearly all school districts, layoffs are currently determined by some version of teacher seniority.  Yet, alternative approaches to personnel reductions may substantially reduce the harm to students from staff reductions relative to layoffs based on seniority.  This policy brief illustrates the differences in New York City public schools that would result when layoffs are determined by seniority in comparison to estimated teacher value-added for fourth and fifth grade teachers employing math and ELA student achievement. We find the differences between seniority and value-added based layoffs are larger and more persistent than we anticipated.  However, as a result of the limited applicability of teacher value-added measures to the full population of teachers as well as concerns about potential mis-measurement of effectiveness associated with using value-added measures even when available, neither seniority nor measures of value-added to student achievement should be the sole criterion determining layoffs.  But ignoring effectiveness measures completely as seniority-based systems do, is also problematic. Instead, the use of multiple measures of effectiveness for layoff decisions holds promise for softening the detrimental effect of layoffs. Policy Brief

The Narrowing Gap in New York City Teacher Qualifications and its Implications for Student Achievement in High-Poverty Schools. August 2007. Donald Boyd, Hamilton Lankford, Susanna Loeb, Jonah Rockoff, and James Wyckoff. Policy Brief

How Changes in Entry Requirements Alter the Teacher Workforce and Affect Student Achievement. November 2005. Donald Boyd, Hamilton Lankford, Pamela Grossman, Susanna Loeb, and James Wyckoff. Policy Brief