Do class size effects differ across grades?

Abstract

This paper contributes to the class size literature by analyzing whether short-run class size eects are constant across grade levels in compulsory school. Results are based on administrative data on all pupils enroled in Danish public schools. Identication is based on a government-imposed class size cap that creates exogenous variation in class sizes. Signicant (albeit modest) negative eects of class size increases are found for children on primary school levels. The eects on math abilities are statistically dierent across primary and secondary school. Larger classes do not aect girls, non-Western immigrants and socioeconomically disadvantaged pupils more adversely than other pupils.

The Danish National Tests at a Glance

“…For example, Andersen et al (2016b) show that a teaching assistant in sixth grade classrooms can close one third of the achievement gap between students of low and high-educated parents documented in this paper. On the other hand, Nandrup (2016) finds that class sizes do not generally affect the achievement gaps in reading and math scores, although, a one-student decrease in class size on average increases test scores by around 0.01 SD. In addition, interventions targeted toward specific groups of students may in fact widen the gap, if the intervention is as least as beneficial for the class peers.…”

“…However, with the introduction of standardized and objective national tests, at multiple grade levels, it is now possible to evaluate the impact of school interventions and programs aimed at improving achievement for specific student groups or grade levels (see e.g. Andersen et al 2016a; Andersen et al 2016b;Nandrup 2016). Thereby improving the possibility for developing evidence-based policies to narrow achievement gaps in Danish public schools.…”

Class Size and Teacher Work: Research Provided to the BCTF in their Struggle to Negotiate Teacher Working Conditions

“…There's no doubt that the greatest obstacle to widespread implementation of class size reduction is the cost brought about by the need for additional teachers, classrooms, facilities, and services. The cost issue has been raised by several critiques of class size reduction policy (Guillemette, 2005;Hanushek, 1981Hanushek, , 1986McRobbie et al, 1998;Tomlinson, 1990), even though many researchers questioning the cost of class size reductions also acknowledge the positive effects on students (Mishel & Rothstein, 2002;Nandrup, 2016;Phelps, 2011). While many of these researchers warn against the use of tax dollars on class size reduction until it has proven its value, there has been little effort to try to determine standards related to cost-benefit or cost-effectiveness for education reforms more broadly.…”

“…Some research suggests that smaller classes may also have beneficial effects on achievement at the secondary level (Krassel & Heinesen, 2014) and even in the post-secondary context (De Paola et al, 2013). However, there have been criticisms that smaller classes are not cost-effective and actually play little role in improving students' outcomes and in closing the gap between learning opportunities for traditionally over-and under-achieving students (Altinok & Kingdon 2012;Bosworth, 2014;Guillemette, 2005;Hanushek, 1986Hanushek, , 1998Koniewski, 2013;Nandrup, 2016;Phelps, 2011).…”

Birth Cohort Size Variation and the Estimation of Class Size Effects

“…This is important since within-school designs provide a number of advantages over commonly applied "Maimonides"-style research designs that exploit variation in class size generated by maximum class size rules as pioneered by Angrist and Lavy (1999) and subsequently used in numerous studies to investigate the effects of class size. 6 First, the within-school design is widely applicable and allows for studying class size effects even if no class size 6 This regression discontinuity approach is used to study the effects of class size by Hoxby (2000) in the United States, Dobbelsteen et al (2002) in the Netherlands, Browning and Heinesen (2007), Krassel and Heinesen (2014) and Nandrup (2016) in Denmark, Bressoux et al (2009) and Piketty and Valdenaire (2006) in France, Asadullah (2005) in Bangladesh, Wößmann (2005) in 10 European countries, Jakubowski and Sakowski (2006) in Poland, Urquiola (2006) in Bolivia, Angrist et al (2017a) in Italy, Falch et al (2017) and Leuven and Oosterbeek (2018) in Norway, and Argaw and Puhani (2018) in Germany.…”