Giving Compass' Take:

· Researchers at the Cato Institute take a look at the factors influencing student success, focusing on how class size affects individual student achievement.

· How does class size relate to student performance? What does this research report tell us? 

· Here's more on class size and student achievement.

What determines student achievement? The usual approach is to think of achievement as the output of an educational production function. Inputs into this educational production function include teacher quality, class size, resources, peer effects (possibly positive spillover effects and negative disruption effects), and past achievement, since achievement builds on past knowledge.

Our research focuses on the effects of class size on achievement. This area has been widely studied in both labor economics and education. Somewhat surprisingly, the estimates are relatively mixed. Even though performance has been related to class size, there has been little attempt to allow for nonmonotonicities. A monotonic relationship between student achievement and class size is always increasing or decreasing. If the relationship is nonmonotonic, student achievement may increase or decrease at different class sizes. For example, it could be that increasing class size initially raises achievement (as students learn from each other as well as from the teacher) and then lowers achievement when congestion effects take over. We explicitly allow for such possibilities and argue that not allowing for nonmonotonicities could be why the literature has found mixed results.

Read the full article about class size by Desire Kedagni, Kala Krishna, Rigissa Megalokonomou, and Yingyan Zhao at Cato Institute.