Journal of Economic Perspectives: Vol. 23 No. 4 (Fall 2009)


Quick Tools:

Print Article Summary
Export Citation
Sign up for Email Alerts Follow us on Twitter


JEP - All Issues

Field Experiments in Class Size from the Early Twentieth Century

Article Citation

Rockoff, Jonah. 2009. "Field Experiments in Class Size from the Early Twentieth Century." Journal of Economic Perspectives, 23(4): 211-30.

DOI: 10.1257/jep.23.4.211


A vast majority of adults believe that class size reductions are a good way to improve the quality of public schools. Reviews of the research literature, on the other hand, have provided mixed messages on the degree to which class size matters for student achievement. Here I will discuss a substantial, but overlooked, body of experimental work on class size that developed prior to World War II. These field experiments did not have the benefit of modern econometrics, and only a few were done on a reasonably large scale. However, they often used careful empirical designs, and the collective magnitude of this body of work is considerable. Moreover, this research produced little evidence to suggest that students learn more in smaller classes, which stands in contrast to some, though not all, of the most recent work by economists. In this essay, I provide an overview of the scope and breadth of the field experiments in class size conducted prior to World War II, the motivations behind them, and how their experimental designs were crafted to deal with perceived sources of bias. I discuss how one might interpret the findings of these early experimental results alongside more recent research.

Article Full-Text Access

Full-text Article (Complimentary)

Additional Materials

Appendix (172.34 KB)


Rockoff, Jonah (Columbia U)

JEL Classifications

I21: Analysis of Education
I28: Education: Government Policy
N32: Economic History: Labor and Consumers, Demography, Education, Health, Welfare, Income, Wealth, and Religion: U.S.; Canada: 1913-


View Comments on This Article (0) | Login to post a comment

Journal of Economic Perspectives

Quick Tools:

Sign up for Email Alerts

Follow us on Twitter

Subscription Information
(Institutional Administrator Access)


JEP - All Issues

Virtual Field Journals

AEA Member Login:

AEAweb | AEA Journals | Contact Us