A comparative look at private and public schools' class size determinants

This paper tests three theories of class size determination: that schools assign better-behaved students, higher quality teachers, or higher-achieving students into larger classes. Furthermore, we estimate how these methodologies differ between public and private schools. Using a nationally representative sample from the USA, we show that, within public schools, third-grade class size is correlated with first-grade ability and, to a lesser extent, first-grade behavior. Private schools, however, appear to assign teachers reporting greater control over school policy to larger classes and teachers with more experience to smaller classes. Class size determination is due to uniquely different processes within public and private schools.