Teacher Quality and its Influence on Student Learning Outcomes - Evaluation of the German Educational Expansion as a natural experiment

Due to the considerable quantitative expansion of secondary education from the 1960s onward in Germany, the number of teachers at Real- and Gesamtschulen and at Gymnasien also more than quadrupled. The resulting immense demand for teachers likely had an impact on who could and would become teachers. This research project from the field of empirical economic research addresses two questions that can be derived from this: First, does the expansion of secondary education have an impact on the career choice decisions of potential teachers, and if so, how exactly does it manifest itself? Second, and on this aspect lies the focus of this project after a possible verification of the first question, do those additional teachers have a different ability to deliver education to their students - with implications for student achievement? In public debate, as in scholarly discourse, this possible aspect of educational expansion has not been considered. This is likely because data sets that would allow us to answer the present research question have not been available. This project uses the National Education Panel Study (NEPS), an innovative dataset that allows us to link detailed characteristics about the reasons for teachers' career choices and school and university performance with subject-specific achievement scores of the students these teachers teach as of 2010. The intuition of the empirical analysis can be outlined as follows: The learning performance of two groups of students in 2010 is compared. One group of students happened to be taught by teachers hired just before the education expansion, and the other is taught by teachers hired just after the education expansion. To identify these two types of teachers, we exploit the fact that educational expansion differs gradually across states in the exact timing of its introduction and its intensity. The empirical answer to these two questions has particular social relevance for at least three reasons: First, it is a society-wide event that potentially affected, and may still affect, a very large number of students: 150,000 additional teachers were hired in higher secondary schools to teach approximately 2.8 million students annually over their working lives. Second, empirical studies suggest that learning achievement gaps during schooling have long-term consequences for success later in life for the students affected. Third, findings on the effects of educational expansion are partly transferable to similar adjustments to state institutions that are currently needed and will be needed in the future, such as the German expansion of day care centers. In particular, the legal right to a daycare place for all children from the age of one also dramatically increases the need for caregivers. This could also make the profession attractive to people whose characteristics are less conducive to child development.