Value-added Based Measures of Teacher Effectiveness and their Determinants in the German National Educational Panel Study

• Applicant: Professor Dr. Ludger Wößmann
• Subject Area: Economic Policy, Applied Economics
• Term: from 2012 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 215810025

The project aims to analyze the effectiveness of teachers and its determinants based on student-level achievement data from the German National Educational Panel Study (NEPS). The existing US literature typically operationalizes teacher effectiveness using teacher fixed effects from value-added models of student achievement, where the estimated teacher fixed effects serve as a proxy for teacher quality. They quantify the overall teacher contribution to student learning, including the impacts of observed as well as unobserved teacher traits. The US evidence suggests that variation in these measures of teacher quality can explain a substantial part of the overall variation in student achievement. It is yet unclear, though, whether such substantial effects are also present in other education systems; no equivalent estimates for Germany exist so far. A first key goal of the project is therefore to fill this gap by exploiting the longitudinal structure of the NEPS data to estimate value-added models of student achievement that include teacher fixed effects. Based on the estimated distribution of teacher quality, we can quantify the effects of having an “effective” teacher on student achievement, captured by the average increase in student achievement associated with a one standard deviation improvement in teacher quality. A particular goal is to compare our estimates with the available US evidence to investigate whether German teachers are more homogenous in terms of effectiveness.A second key goal of the project is to study the determinants of teacher quality. Despite the estimated substantial impacts of high-quality teachers, the precise characteristics defining teacher quality remain a subject of ongoing research. The NEPS survey information exceeds the information on teacher characteristics typically available in large-scale linked student-teacher datasets. This allows a new set of analyses of the determinants of teacher quality, covering three broad categories of teacher characteristics: first, basic teacher traits such as gender, age, experience, and teacher training; second, variables describing the attitudes and behavior of teachers; and third, unique NEPS data on the course of teacher studies and the selection into the teaching profession. For example, we can test whether teachers who followed typical teacher education differ systematically from “Quereinsteiger” who decided to become teacher at later stages.We address the question of determinants of teacher quality using two distinct methodological approaches that both study the relationship between teacher traits and within-student variation in academic achievement to eliminate the effect of unobserved student and school characteristics. The first approach is based on the estimated value-added measures of teacher quality that utilize variation in student achievement over time. The second approach uses variation in student achievement between two subjects. Since the two methodological approaches are based on different identifying assumptions and we can implement them based on a single source of data, we will also be able to assess to what extent estimated effects of teacher traits depend on the chosen estimation method.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 1646: Education as a Lifelong Process. Analysing Data of the National Educational Panel Study (NEPS)
• Participating Person: Professor Dr. Guido Schwerdt