SCHOOL FOR THOUGHT

The devil is in the class size details, especially the additional costs

Everybody likes smaller classes. Teachers’ unions like them because smaller classes require more teachers. Teachers like them, because they mean less work and more time with individual students. Parents like them because they think their kids will learn more. Politicians like them because promising smaller classes gets them votes. But because a class size reduction of even one student is very expensive, it is important to ask how much we would have to spend in order to achieve significant increases in student learning and other positive outcomes.

This very thorough scholarly paper examines worldwide research on class reductions, concluding “Class-size reduction has been shown to work for some students in some grades in some states and countries, but its impact has been found to be mixed or not discernable in other settings and circumstances that seem similar.”

On balance, the evidence suggests that only very large reductions, in the order of 7-10 students per class, will lead to significant long-term positive effects. Since a one-student decrease in the pupil-teacher ratio in the US has been estimated to cost approximately $12 billion every year in teacher salaries alone (no estimate is given of the cost of the additional classroom space requirements), a reduction of 7 or more students would be ruinously expensive.

There are other measures that governments can implement to increase student learning, and most of them are considerably less costly than class size reductions. Some examples would include school choice, promotion of research-based teaching methods and materials, elimination of the requirement for teachers to attend a faculty of education, and decentralized decision-making. 

As the paper concludes, “The costs and benefits of class-size mandates need to be carefully weighed against all of the alternatives when difficult budget and program decisions must be made.”