This study provides empirical evidence of the relation between class size and classroom behavioral climate, in particular discipline problems, in comprehensive school. Classroom behavioral climate and class size are both components of the quality of education. Lack of good classroom behavioral climate in the class may have harmful effects on learning, and it is related to overall learning environment. Class size on the other hand is related to physical elements of quality learning environment and it relates both to students’ learning and teacher’s working conditions.

The empirical literature has shown that class size is related to school achievement (Angrist & Lavy, 1999; Krueger, 1999), cognitive and non-cognitive skills, completing education and wages (Peter Fredriksson, Öckert, & Oosterbeek, 2013), but the mechanisms behind these effects are far less understood. Theoretically there are at least two mechanisms. First, teachers and parents may react on class size (Albornoz, 2010), and second, class size is related to classroom behavioral climate (Lazear, 2001). It has been empirically confirmed that parents and teachers react on class size, for example, teachers may shift towards full class instruction, and parents may move to another school as a response to an increase in class size (P. Fredriksson, Ockert, & Oosterbeek, 2016). However, the evidence on the effects of class size on classroom behavioral climate is limited.

A theoretical model related to class size and lack of good classroom behavioral climate, conceptualized as classroom disruption, was presented by Lazear (2001). Classroom disruption occurs when disruptive student takes up teacher’s time in a way which is not useful to other students by, for example, misbehaving or asking irrelevant questions. In case of disruptive behavior, learning is reduced for all students in the class. Classroom disruption is harmful for students, because it may impede learning (Erätuuli & Puurula, 1992) or reduce interaction and time spent on teaching in class (Blatchford, Bassett, Goldstein, & Martin, 2003). Empirical research has illustrated that reduction in class size is associated with decline in time spent on discipline (Betts & Shkolnik, 1999), and that potentially disruptive children (Kristoffersen, Krægpøth, Nielsen, & Simonsen, 2015) and students with serious behavioral difficulties (Horoi & Ost, 2015) reduce the academic performance of their peers. As class size has long lasting effects at the individual level (Peter Fredriksson et al., 2013), and as reducing class size is expensive for the society, it is important to understand the mechanisms behind the class size effects. In the present study we aim to shed more light on the relation between class size and a lack of good classroom behavioral climate.

Albornoz, F. (2010). Incentives , resources and the organization of the school system ∗. Working Paper, (July), 1–34. Angrist, J., & Lavy, V. (1999). of Class Size on Scholastic Achievement *. The Quarterly Journal of Economics, 114(2), 533–575. https://doi.org/10.1162/003355399556061 Betts, J. R., & Shkolnik, J. L. (1999). The Behavioral Effects of Variations in Class Size: The Case of Math Teachers. Educational Evaluation and Policy Analysis, 21(2), 193–213. https://doi.org/10.3102/01623737021002193 Blatchford, P., Bassett, P., Goldstein, H., & Martin, C. (2003). Are Class Size Differences Related to Pupils’ Educational Progress and Classroom Processes? Findings from the Institute of Education Class Size Study of Children Aged 5-7 Years. British Educational Research Journal, 29(5), 709–730. https://doi.org/10.1080/0141192032000133668 Erätuuli, M., & Puurula, A. (1992). Miksi häiritset minua: Opettajan näkökulma työrauhahäiriöihin yläasteella. Yliopistopaino. Fredriksson, P., Ockert, B., & Oosterbeek, H. (2016). Parental Responses to Public Investments in Children: Evidence from a Maximum Class Size Rule. Journal of Human Resources, 51(4), 832–868. https://doi.org/10.3368/jhr.51.4.1114-6779R1 Fredriksson, P., Öckert, B., & Oosterbeek, H. (2013). Long-term effects of class size. The Quarterly Journal of Economics, (2000), 249–285. https://doi.org/10.1093/qje/qjs048.Advance Horoi, I., & Ost, B. (2015). Disruptive peers and the estimation of teacher value added. Economics of Education Review, 49, 180–192. https://doi.org/10.1016/j.econedurev.2015.10.002 Kristoffersen, J. H. G., Krægpøth, M. V., Nielsen, H. S., & Simonsen, M. (2015). Disruptive school peers and student outcomes. Economics of Education Review, 45, 1–13. https://doi.org/10.1016/j.econedurev.2015.01.004 Krueger, A. B. (1999). Experimental estimates of education production functions. The Quarterly Journal of Economics, 114(2), 497–532. https://doi.org/10.1162/003355399556052 Lazear, E. P. (2001). Educational Production. Quarterly Journal of Economics, 116(3), 777–803. https://doi.org/10.1162/00335530152466232 Levin, J., & Nolan, J. (2010). Principles of classroom management: A professional decision-making model (6th ed.). Boston: Pearson. Ministry of Education and Culture (2014). Opetusryhmien tila Suomessa. Selvitys eduskunnan sivistysvaliokunnalle esi- ja perusopetuksen opetusryhmien nykytilasta.