The Effects of Class Size on Student Achievement in Higher Education: Applying an Earnings Function

This paper uses an earnings function to model how class size affects the grade students earn. We test the model using an ordinal logit with and without fixed effects on 363,023 undergraduate observations. We find that class size negatively affects grades. Average grade point declines as class size increases, precipitously up to class sizes of ten, and more gradually but monotonically through class sizes of 400 plus. The probability of getting a B plus or better declines from 0.9 for class sizes 20 to about 0.5 for class sizes of 120 and almost 0.4 for class sizes of 400

The Effects of Class Size on Student Achievement in Higher Education

We model how class size affects the grade higher education students earn and we test the model using an ordinal logit with and without fixed effect on over 760,000 undergraduate observations from a northeastern public university. We find that class size negatively affects grades for a variety of specifications and subsets of the data, as well as for the whole population. Average grade point declines as class size increases, precipitously up to class sizes of twenty, and more gradually but monotonically through larger class sizes. Evidence suggests that this phenomena is not exclusively caused by a “small-class” effect.cheri_wp67.pdf: 945 downloads, before Oct. 1, 2020

DO NOT QUOTE The Effects of Class Size on Student Achievement in Higher Education: Applying an Earnings Function a

This study is an extension of an analysis started by Jack Keil and Peter Partell of Binghamton University, Office of Institutional Research in the late 1990s. We wish to thank them for their help and insights. We would also like to thank Jessica Richards who has helped enormously in editing, critiquing and creating the tables and charts used in the paper. Yu Zhu and Hester Han have also brought their considerable analytic expertise to the project. All errors and omissions are the responsibility of the authors. This paper uses an earnings function to model how class size affects the grade students earn. We test the model using an ordinal logit with and without fixed effects on 363,023 undergraduate observations. We find that class size negatively affects grades. Average grade point declines as class size increases, precipitously up to class sizes of ten, and more gradually but monotonically through class sizes of 400 plus. The probability of getting a B plus or better declines from 0.9 for class sizes 20 to about 0.5 for class sizes of 120 and almost 0.4 for class sizes of 400.