Class Size Effects on Fourth-Grade Mathematics Achievement: Evidence From TIMSS 2011

ABSTRACT

Class size reduction policies have been widely implemented around the world in recent years. However, findings about the effects of class size on student achievement have been mixed. This study examines class size effects on fourth-grade mathematics achievement in 14 European countries using data from TIMSS (Trends in International Mathematics and Science Study) 2011. We employ quasi-experimental methodology (i.e., instrumental variables and regression discontinuity) to facilitate causal inferences of class size effects. Although we find some evidence of class size effects in Romania and the Slovak Republic, overall there are no systematic patterns of class size effects across countries. The results indicate that in most European countries class size reduction may not improve mathematics achievement in fourth grade.

KEYWORDS:

• class size
• mathematics achievement
• TIMSS
• instrumental variables
• regression discontinuity

EDITORS

This article was reviewed and accepted under the editorship of Carol McDonald Connor and Spyros Konstantopoulos.

Notes

¹ We ran OLS and IV analyses using a rule of 30 for these three countries as well as the rules shown in Figure 2. The results were similar.

² We also calculated the school-level cluster robust standard errors for both OLS and IV analyses. The results were quite similar to the jackknife robust standard errors.

³ We also conducted the same analysis using +/−10 discontinuity samples and the results were quite similar to those from the +/−5 sample.

⁴ We ran several models with different sets of covariates and the results were quite similar and robust. We only reported the results from models that include all possible covariates in this article.