The role of class-size in primary education has between discussed before on this blog. Earlier this year Kevin and Mark both posted interesting comments on the analysis of secondary data. In addition, I recently mentioned that data on primary-school class sizes in Ireland are available for the last four years by primary-school and class-room. Those looking for an introduction to how economists view the importance of class size in primary education could do worse than investigate this debate between Alan Krueger, Eric Hanushek and Jennifer King Rice.
"Alan Krueger maintains that smaller class sizes can improve students’ performance and future earnings prospects. He challenges Prof. Hanushek’s widely cited analysis of the class size literature, arguing that it gives disproportionate weight to single studies that include a large number of estimates... Jennifer King Rice brings a third-party perspective to the debate. She addresses each author’s arguments and focuses on the policy implications of the class size literature."
As educational achievement in higher education is often discussed on this blog, it seems salient to ask what we know about the importance of class size in higher education. To begin, it is helpful to point out that much of the work using education production functions has concentrated on the educational attainment of pupils in compulsory schooling, with less attention paid to higher education (Arulampalam, Naylor and Smith, 2009). The common inputs in education production functions are things like school resources, teacher quality, and family attributes, and the outcome is student achievement (Hanushek, 2007). However, there is a precedent for the theoretical consideration of higher education production functions (Freire and Silva, 1975; Johnson, 1978; Hopkins, 1990; Douglas and Sulock, 1995). There is also a much wider empirical literature on higher education production functions, in which researchers give attention to student inputs, in particular: lecture attendance and additional hours of study.
Looking at the evidence on class size in higher education, one result is that smaller classes do not translate into gains in achievement (Martins and Walker, 2006). Looking at economics students only, Kennedy and Siegfried (1997) find the same result i.e. that class size does not affect student achievement. Other work by Gleason shows that the same holds for mathematics students.
The opposite result (that class size matters) is found in a study examining peer effects and class size in higher education; Machado and Vera-Hernandez (2010) find that class size negatively influences medium ability college students. Dillon and Kokkelenberg (2002) show that class size "has a negative logarithmic relationship to grades and that the effect on class size on grades differs across different category of student."
In a recent Vox article, Bandiera, Larcinese and Rasul (2010) state that the effect of increasing class size in tertiary education is not yet well understood. Drawing on their article forthcoming in the Economic Journal, Bandiera, Larcinese and Rasul describe how they estimate the effects of class size on students’ exam performance by comparing the same student’s performance to her own performance in courses with small and large class sizes. "Going from the average class of 56 to a class size of 89 would decrease the mark by 9% of the observed variation in marks within a given student. The effect is almost four times larger for students in the top 10%."
It seems that the debate on class size in higher education is just as lively as the debate on class size in primary education.