The Effects of Class Size on the Long-Run Growth in Reading Abilities and Early Adult Outcomes in the Christchurch Health and Development Study
The conflicting evidence over class size effects drawn from observational (or correlational) studies on academic achievement or labor market outcomes has provoked great debate in both academic and public policy arenas. The recent experimental evidence from the United States due to the Project STAR demonstration run in Tennessee in the 1980s has added strong evidence in favor of one type of an effect, whereby initial test score gains were maintained only through sustained smaller class sizes. But this has not resolved the debate by any means. In this paper we utilize the unique feature of the Christchurch Health and Development Study (CHDS) in that children are sampled for extremely long individual histories of their class size experiences as well as their test score and early adult outcomes. We argue that one implication of Project STAR is that only persistent class size reduction policies may have detectable effects, and so the long histories of the type recorded by the CHDS are necessary to detect class size effects. We account for the observational nature of the CHDS (in that children were not randomly assigned to different class sizes) by examining the long-run trends in test score growth, rather than levels. Consistent with the experimental evidence, we found statistically and economically significant effects of children being assigned to persistently smaller classes on both childhood test score growth as well as on early adult outcomes such as completed education and unemployment experiences. Our analysis points the way towards the unification of experimental and observational evidence on class size effects, as well as highlighting several possible pitfalls in the analysis of observational data on this topic. It also serves as a platform by which further experimental studies on class size might be designed to verify or falsify some of the hypotheses raised in this report, and so further unify the entire literature on this topic.
|Date of creation:||2001|
|Date of revision:|
|Contact details of provider:|| Postal: New Zealand Treasury, PO Box 3724, Wellington, New Zealand|
Phone: +64-4-472 2733
Fax: +64-4-473 0982
Web page: http://www.treasury.govt.nz
More information through EDIRC
Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:
- Eric A. Hanushek, . "The Evidence on Class Size," Wallis Working Papers WP10, University of Rochester - Wallis Institute of Political Economy.
- Zvi Griliches & Jerry A. Hausman, 1984.
"Errors in Variables in Panel Data,"
NBER Technical Working Papers
0037, National Bureau of Economic Research, Inc.
When requesting a correction, please mention this item's handle: RePEc:nzt:nztwps:01/14. See general information about how to correct material in RePEc.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Web and Publishing Team, The Treasury)
If references are entirely missing, you can add them using this form.