The Impact of All-Day Schools on Student Achievement - Evidence from Extending School Days in German Primary Schools

This paper studies the effect of longer school days - induced by voluntary all-day programs in German primary schools - on school performance. We combine data from the National Educational Panel Study covering 5348 primary school students with municipality-level information on all-day school investments. Facing the challenge of selection into all-day school programs, we instrument all-day school expansion with construction subsidies from a large federal investment project. Results imply that all-day programs lead to improvements in language and math skills as measured by teacher assessments and to a higher probability of being recommended for the academic track following primary school. Heterogeneity analysis suggests that voluntary all-day programs did not reduce educational inequality.