- David D. Liebowitz
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David D. Liebowitz
School principals are viewed as critical actors to improve student outcomes, but there remain important methodological questions about how to measure principals’ effects. We propose a framework for measuring principals’ contributions to student outcomes and apply it empirically using data from Tennessee, New York City, and Oregon. As commonly implemented, value-added models misattribute to principals changes in student performance caused by unobserved time-varying factors over which principals exert minimal control, leading to biased estimates of individual principals’ effectiveness and an overstatement of the magnitude of principal effects. Based on our framework, which better accounts for bias from time-varying factors, we find that little of the variation in student test scores or attendance is explained by persistent effectiveness differences between principals. Across contexts, the estimated standard deviation of principal value-added is roughly 0.03 student-level standard deviations in math achievement and 0.01 standard deviations in reading.
Many education policymakers and system leaders prioritize recruiting and developing effective school leaders as key mechanisms to improve school climate and student learning. Despite efforts to select and support successful school leaders, however, relatively little is understood about the prior professional experiences and skillsets that principals possess upon entry into their positions. In this descriptive paper, we use 14 years of administrative data on all educators in Oregon to trace the prior professional experiences and instructional effectiveness of those who become school leaders. We highlight that many principals in Oregon acquire educational leadership experience outside the assistant principal role and outside of the school district in which they serve as principals. We also find that when future school leaders were teachers, they improved student achievement at modestly higher rates than their peers. Insight into these topics has the potential to inform the pre-service training, recruitment and professional development of school leaders.
Policy makers periodically consider using student assignment policies to improve educational outcomes by altering the socio-economic and academic skill composition of schools. We exploit the quasi-random reassignment of students across schools in the Wake County Public School System to estimate the academic and behavioral effects of being reassigned to a different school and, separately, of shifts in peer characteristics. We rule out all but substantively small effects of transitioning to a different school as a result of reassignment on test scores, course grades and chronic absenteeism. In contrast, increasing the achievement levels of students' peers improves students' math and ELA test scores but harms their ELA course grades. Test score benefits accrue primarily to students from higher-income families, though students with lower family income or lower prior performance still benefit. Our results suggest that student assignment policies that relocate students to avoid the over-concentration of lower-achieving students or those from lower-income families can accomplish equity goals (despite important caveats), although these reassignments may reduce achievement for students from higher-income backgrounds.
Teacher evaluation policies seek to improve student outcomes by increasing the effort and skill levels of current and future teachers. Current policy and most prior research treats teacher evaluation as balancing two aims: accountability and skill development. Proper teacher evaluation design has been understood as successfully weighting the accountability and professional growth dimensions of policy and practice. I develop a model of teacher effectiveness that incorporates improvement from evaluation and detail conditions which determine the effectiveness of teacher evaluation for growth and accountability at improving student outcomes. Drawing on empirical evidence from the personnel economics, economics of education and measurement literatures, I simulate the long-term effects of a set of teacher evaluation policies. I find that those that treat evaluation for accountability and evaluation for growth as substitutes outperform policies that treat them as complements. I conclude that optimal teacher evaluation policies would impose accountability on teachers performing below a defined level and above which teachers would be subject to no accountability pressure but would receive intensive instructional supports.
Despite frequent political and policy debates, the effects of imposing accountability pressures on public school teachers are empirically indeterminate. In this paper, we study the effects of accountability in the context of teacher responses to student behavioral infractions in the aftermath of teacher evaluation reforms. We leverage cross-state variation in the timing of state policy implementation to estimate whether teachers change the rate at which they remove students from their classrooms. We find that higher-stakes teacher evaluation had no causal effect on the rates of disciplinary referrals, and we find no evidence of heterogeneous effects for grades subject to greater accountability pressures or in schools facing differing levels of disciplinary infractions. Our results are precisely estimated and robust to a battery of specification checks. Our findings provide insights on the effects of accountability policy on the black-box of classroom practice and highlight the loose-coupling of education policy and teacher behaviors.