Teacher-to-classroom assignment and student achievement

We study the effects of counterfactual teacher-to-classroom assignments on average student achievement in U.S. elementary and middle schools. We use the Measures of Effective Teaching (MET) experiment to semiparametrically identify the average reallocation effects (AREs) of such assignments. Our identification strategy exploits the random assignment of teachers to classrooms in MET schools. To account for non-compliance of some students and teachers to the random assignment, we develop and implement a semiparametric instrumental variables estimator. We find that changes in within-district teacher assignments could have appreciable effects on student achievement. Unlike policies that aim at changing the pool of teachers (e.g., teacher tenure policies or class-size reduction measures), alternative teacher-to-classroom assignments do not require that districts hire new teachers or lay off existing ones; they raise student achievement through a more efficient deployment of <i>existing</i> teachers.