Latest Reports from the Education Policy Center

In the face of unavoidable teacher layoffs, policymakers must juggle a variety of issues in choosing the best criteria for laying off teachers. The standard approach in most school districts relies on measures of seniority. Analyzing data on 4th and 5th grade teachers in New York City public schools, CALDER researchers find substantial differences in which teachers get cut under a seniority-based layoff policy versus a policy based on teacher effectiveness (value-added). The authors model the two layoff scenarios to respond to a (fictional) budget shortfall equivalent. The bottom line is that informing teacher layoffs with information about effectiveness, while not perfect, can improve student performance.

Search theory suggests early career job changes lead to better matches that benefit both workers and firms, but this may not hold true in teacher labor markets characterized by salary rigidities, barriers to entry, and substantial differences in working conditions. Education policy makers are particularly concerned that teacher turnover may have adverse effects on the quality of instruction in schools serving predominantly disadvantaged children. Although these schools experience higher turnover, on average, than other schools, the impact on the quality of instruction depends on whether more productive teachers are more likely to depart. In Texas, the availability of matched panel data of students and teachers enables the isolation of teachers' contributions to achievement. Teachers who remain in their school tend to outperform those who leave, particularly those who exit Texas public schools entirely. This gap is larger for schools serving mainly low income students— evidence that high turnover is not nearly as damaging as many suggest.

This study is the first to exploit policy variation within the same state to examine the effects of school accountability on tacher job changes. Using student-level data from Florida State the authors measure the degree to which schools and teachers were "surprised" by the change in the school grading system (in summer of 2002)— what they refer to as an "accountability shock"— by observing the mobility decisions of teachers in the years before and after the school grading change. They find over half of all schools in the state experience an accountability "shock" due to this grading change. Also, teachers are more likely to leave schools facing increased accountability pressure— and even more likely to leave schools shocked downward to a grade of "F". They are less likely to leave schools facing decreased accountability pressure. Moreover, schools facing increased pressure experience an increase in the quality of teachers who leave or stay and schools with no accontability shock experience no significant change to the quality of teachers that leave or stay.

Voucher options like tuition tax credit-funded scholarship programs have become increasingly popular in recent years. This study examines the effects of private school competition on public school students' test scores in the wake of Florida's Corporate Tax Credit Scholarship program which offered scholarships to eligible low-income students to attend private schools. The authors examine whether students in schools exposed to a more competitive private school landscape saw greater improvement in their students' test scores after the introduction of the program, than did students in schools that faced less competition. Greater degrees of competition are associated with greater improvements in students' test scores following the introduction of the program. The findings are not an artifact of pre-policy trends; the degree of competition from nearby private schools matters only after the announcement of the new program, which makes nearby private competitors more affordable for eligible students. Also, schools that we would expect to be most sensitive to competitive pressure see larger improvements in their test scores as a result of increased competition.

The gold standard in making causal inference on program effects is a randomized trial. Most randomization designs in education randomize classrooms or schools rather than individual students. Such "clustered randomization" designs have one principal drawback: They tend to have limited statistical power or precision. This study aims to provide empirical information needed to design adequately powered studies that randomize schools using data from Florida and North Carolina. The authors assess how different covariates contribute to improving the statistical power of a randomization design and examine differences between math and reading tests; differences between test types (curriculum-referenced tests versus norm-referenced tests); and differences between elementary school and secondary school, to see if the test subject, test type, or grade level makes a large difference in the crucial design parameters. Finally they assess bias in 2-level models that ignore the clustering of students in classrooms.

An estimated 3.3 million young men and women will leave high school in June with - or without - a diploma. The speed with which they secure steady employment or a seat in another classroom differs markedly by race. Black high school graduates, for instance, will take 20 percent longer than their white counterparts to land a job lasting six or more months, according to forthcoming research from the Urban Institute.

Can value-added measures provide valuable information to assess the quality of teachers and to create incentives for improvement? CALDER researchers tackle this important and timely question by describing the analytic framework of value-added measures, by identifying methodological concerns about value-added estimation and ways to mitigate them, and by discussing the policy uses of value-added estimates of teacher effectiveness.

Defined benefit pension systems concentrate benefits on career teachers and impose costs on mobile teachers. This study analyzes the magnitude of these effects. Compared to a neutral system, often about half of an entering cohort's net pension wealth is redistributed to teachers who separate in their fifties from those who separate earlier, with some variation across states. This implies large costs for interstate mobility. Teachers who split a thirty-year career between two pension plans often lose over half their net pension wealth compared to teachers who complete a career in a single system. Likely explanations include the relative influence of senior versus junior educators in interest group politics and a coordination problem between states.

This study presents a generalization to the standard career concerns model and applies it to the public teacher labor market. The model predicts that optimal teacher effort levels decline with both tenure at a school and experience, all things being equal. Using administrative data from North Carolina spanning 14 school years through 2008, the study finds significant changes in teacher sick leave consistent with the generalized career concerns model. There is evidence that observed behaviors cannot be due to the endogeneity of teacher mobility decisions alone as well as evidence suggestive of teacher shirking. In sum, teachers exert considerable discretion over their own effort levels in response to these incentives, with important policy implications.

Reforming teacher tenure is an idea that appears to be gaining traction with the underlying assumption that one can infer, to a reasonable degree, how well a teacher will perform over her career based on estimates of her early-career effectiveness. In this paper, the authors explore the potential for using value-added models to estimate performance and inform tenure decisions. There is little evidence that the variation of teacher effects change over teacher careers, but strong evidence that prior year estimates of job performance predict student achievement, even when there is a multi-year lag between the two.