Does Smaller Mean Better? Evidence from the China Education Panel Survey on Class Size and Student Achievement

Authors

  • Jianjiang Luo

    Faculty of Education, Northeast Normal University, Changchun 130024, China

    The High School Attached to Northeast Normal University, Changchun 130021, China
  • Jiawei Gu

    School of Education, Renmin University of China, Beijing 100872, China

DOI:

https://doi.org/10.30564/jiep.v8i2.12076
Received: 10 July 2025 | Revised: 24 August 2025 | Accepted: 1 September 2025 | Published Online: 8 September 2025

Abstract

This study investigates the causal effect of class size on student academic achievement in China’s compulsory education system, leveraging the institutional feature of randomized student assignment to establish a quasi-experimental framework. Using nationally representative data from the China Education Panel Survey (CEPS) and applying a two-level hierarchical linear model, the research effectively addresses endogeneity arising from non-random class allocation. Results reveal that large classes exert a statistically significant and negative impact on students’ academic performance, even after controlling for individual, family, and school-level characteristics. Specifically, moving from medium to large classes reduces achievement by approximately 0.03 standard deviations—a magnitude comparable to the effect of parental education. The analysis further identifies that class-size distribution is primarily determined by institutional and demographic factors, such as urbanization, school ranking, and parental education levels, indicating both structural and demand-side sources of educational inequality. Robustness checks confirm the linearity and stability of these findings. These findings provide credible causal evidence that class size is not merely a contextual variable but a critical determinant of educational outcomes and a key mechanism through which inequality is produced and mediated. The results carry substantial policy implications for resource allocation and equity, particularly for large, rapidly developing economies grappling with intense demographic pressure on their urban education systems.

Keywords:

Class Size; Academic Performance; Educational Equity; Multilevel Modeling; China Education Panel Survey (CEPS)

References

[1] Webb, C.E., 2003. The Effects of a Class Size Reduction on Elementary Student Reading Achievement in a Midwestern Urban School District [PhD. thesis]. The University of Iowa: Iowa City, IA, USA . pp. 22–45.

[2] Rice, J.K., 1999. The Impact of Class Size on Instructional Strategies and the Use of Time in High School Mathematics and Science Courses. Educational Evaluation and Policy Analysis. 21(2), 215–229. DOI: https://doi.org/10.3102/01623737021002215

[3] Greenwald, R., Laine, R., Hedges, L., 1994. An Exchange: Part I: Does Money Matter? A Meta-Analysis of Studies of the Effects of Differential School Inputs on Student Outcomes. Educational Researcher. 23(3), 5–14.

[4] Brewer, D.J., Krop, C., Gill, B.P., et al., 1999. Estimating the Cost of National Class Size Reductions Under Different Policy Alternatives. Educational Evaluation and Policy Analysis. 21(2), 179–192. DOI: https://doi.org/10.3102/01623737021002179

[5] Howie, S.J., 2005. Contextual Factors at the School and Classroom Level Related to Pupils’ Performance in Mathematics in South Africa. Educational Research & Evaluation. 11(2), 123–140. DOI: https://doi.org/10.1080/13803610500110703

[6] Winne, P.H., Nesbit, J.C., 2010. The Psychology of Academic Achievement. Annual Review of Psychology. 61(1), 653–678. DOI: https://doi.org/10.1146/annurev.psych.093008.100348

[7] Raimondo, H.J., Esposito, L., Gershenberg, I., 1990. Introductory Class Size and Student Performance in Intermediate Theory Courses. The Journal of Economic Education. 21(4), 369–382. DOI: https://doi.org/10.2307/1182537

[8] Siegfried, J.J., Kennedy, P.E., 1995. Does Pedagogy Vary with Class Size in Introductory Economics? The American Economic Review. 85(2), 347–351.

[9] Lippman, S.A., 1990. On the Optimality of Equal Class Sizes. Economics Letters. 33(2), 193–196. DOI: https://doi.org/10.1016/0165-1765(90)90168-Z

[10] Hanushek, E.A., 1999. Some Findings from an Independent Investigation of the Tennessee STAR Experiment and from Other Investigations of Class Size Effects. Educational Evaluation and Policy Analysis. 21(2), 143–163. DOI: https://doi.org/10.3102/01623737021002143

[11] Angrist, J.D., Lavy, V., 1999. Using Maimonides’ Rule to Estimate the Effect of Class Size on Scholastic Achievement. The Quarterly Journal of Economics. 114(2), 533–575. DOI: https://doi.org/10.1162/003355399556061

[12] Jepsen, C., 2015. Class Size: Does It Matter for Student Achievement? IZA World of Labor. Article No. 190. DOI: https://doi.org/10.15185/izawol.190

[13] Nandrup, A.B., 2015. Do Class Size Effects Differ Across Grades? Education Economics. 24(1), 83–95. DOI: https://doi.org/10.1080/09645292.2015.1099616

[14] Li, W., Konstantopoulos, S., 2016. Class Size Effects on Fourth-Grade Mathematics Achievement: Evidence from TIMSS 2011. Journal of Research on Educational Effectiveness. 9(4), 503–530. DOI: https://doi.org/10.1080/19345747.2015.1105893

[15] Hanushek, E.A., 1999. The Evidence on Class Size. In: Mayer, S.E., Peterson, P. (eds.). Earning and Learning: How Schools Matter. Brookings Institution: Washington, DC, USA. pp. 131–168.

[16] Li, X., Li, M., 2021. The Effect of Large and Small Class Size in Compulsory Education in China. Rangsit Journal of Educational Studies. 8(1), 46–58.

[17] Shen, T., Konstantopoulos, S., 2021. Estimating Causal Effects of Class Size in Secondary Education: Evidence from TIMSS. Research Papers in Education. 36(5), 507–541. DOI: https://doi.org/10.1080/02671522.2019.1697733

[18] Sohn, K., 2016. A Review of Research on Project STAR and Path Ahead. School Effectiveness and School Improvement. 27(2), 116–134. DOI: https://doi.org/10.1080/09243453.2014.994643

[19] Educational Research Service, 1980. Class Size Research: A Critique of Recent Meta-Analyses. Phi Delta Kappan. 62(4), 239–241.

[20] Borland, M.V., Howsen, R.M., Trawick, M.W., 2005. An Investigation of the Effect of Class Size on Student Academic Achievement. Education Economics. 13(1), 73–83. DOI: https://doi.org/10.1080/0964529042000325216

[21] Ding, W., Lehrer, S.F., 2010. Estimating Treatment Effects from Contaminated Multiperiod Education Experiments: The Dynamic Impacts of Class Size Reductions. The Review of Economics and Statistics. 92(1), 31–42. DOI: https://doi.org/10.1162/rest.2009.11453

[22] Angrist, J.D., Lavy, V., Leder-Luis, J., et al., 2019. Maimonides Rule Redux. American Economic Review: Insights. 1(3), 309–324. DOI: https://doi.org/10.1257/aeri.20180120

[23] Kedagni, D., Krishna, K., Megalokonomou, R., et al., 2021. Does Class Size Matter? How, and at What Cost? European Economic Review. 133, 103664. DOI: https://doi.org/10.1016/j.euroecorev.2021.103664

[24] Lazear, E.P., 2001. Educational Production. The Quarterly Journal of Economics. 116(3), 777–803. DOI: https://doi.org/10.1162/00335530152466232

[25] Tetzlaff, L., Hartmann, U., Dumont, H., et al., 2022. Assessing Individualized Instruction in the Classroom: Comparing Teacher, Student, and Observer Perspectives. Learning and Instruction. 82, 101655. DOI: https://doi.org/10.1016/j.learninstruc.2022.101655

[26] Laitsch, D., Nguyen, H., Younghusband, C.H., 2021. Class Size and Teacher Work: Research Provided to the BCTF in Their Struggle to Negotiate Teacher Working Conditions. Canadian Journal of Educational Administration and Policy. 196, 83–101.DOI: https://doi.org/10.7202/1078519ar

[27] Finn, J.D., Pannozzo, G.M., Achilles, C.M., 2003. The “Why Is” of Class Size: Student Behavior in Small Classes. Review of Educational Research. 73(3), 321–368. DOI: https://doi.org/10.3102/00346543073003321

[28] Levin, J., 2001. For Whom the Reductions Count: A Quantile Regression Analysis of Class Size and Peer Effects on Scholastic Achievement. Empirical Economics. 26(1), 221–246. DOI: https://doi.org/10.1007/s001810000054

[29] Barrett, N., Toma, E.F., 2013. Reward or Punishment? Class Size and Teacher Quality. Economics of Education Review. 35, 41–52. DOI: https://doi.org/10.1016/j.econedurev.2013.03.001

[30] Blatchford, P., Bassett, P., Goldstein, H., et al., 2003. Are Class Size Differences Related to Pupils' Educational Progress and Classroom Processes? Findings from the Institute of Education Class Size Study of Children Aged 5–7 Years. British Educational Research Journal. 29(5), 709–730. DOI: https://doi.org/10.1080/0141192032000133668

[31] Bosworth, R., Caliendo, F., 2007. Educational Production and Teacher Preferences. Economics of Education Review. 4, 487–500. DOI: https://doi.org/10.1016/j.econedurev.2005.04.004

[32] Krueger, A.B., Whitmore, D.M., 2001. The Effect of Attending a Small Class in the Early Grades on College-Test Taking and Middle School Test Results: Evidence from Project Star. Economic Journal. 111(468), 1–28. DOI: https://doi.org/10.1111/1468-0297.00586

[33] Bonesronning, H., 2003. Class Size Effects on Student Achievement in Norway: Patterns and Explanations. Southern Economic Journal. 69(4), 952–965. DOI: https://doi.org/10.1002/j.2325-8012.2003.tb00542.x

[34] Addonizio, M.F., Phelps, J.L., 2000. Class Size and Student Performance: A Framework for Policy Analysis. Journal of Education Finance. 26(2), 135–156.

[35] Dobbelsteen, S., Levin, J., Oosterbeek, H., 2002. The Causal Effect of Class Size on Scholastic Achievement: Distinguishing the Pure Class Size Effect from the Effect of Changes in Class Composition. Oxford Bulletin of Economics and Statistics. 64(1), 17–38. DOI: https://doi.org/10.1111/1468-0084.00003

[36] Boozer, M., Rouse, C., 2001. Intraschool Variation in Class Size: Patterns and Implications. Journal of Urban Economics. 50(1), 163–189. DOI: https://doi.org/10.1006/juec.2001.2216

[37] Hoxby, C.M., 2000. The Effects of Class Size on Student Achievement: New Evidence from Population Variation. The Quarterly Journal of Economics. 115(4), 1239–1285. DOI: https://doi.org/10.1162/003355300555060

[38] Opatrny, M., Havranek, T., Irsova, Z., et al., 2023. Publication Bias and Model Uncertainty in Measuring the Effect of Class Size on Achievement. IES Working Papers 19/2023. IES FSV, Charles University: Prague, Czech Republic. Available from: https://ies.fsv.cuni.cz/sites/default/files/uploads/files/wp_2023_19_opatrny%2C%20havranek%2C%20irsova%2C%20scasny.pdf

Downloads

How to Cite

Luo, J., & Gu, J. (2025). Does Smaller Mean Better? Evidence from the China Education Panel Survey on Class Size and Student Achievement . Journal of International Education and Practice, 8(2), 14–29. https://doi.org/10.30564/jiep.v8i2.12076

Issue

Vol. 8 , Iss. 2 (December 2025): In Progress

Article Type

ARTICLE

License

Copyright © 2025 Jianjiang Luo, Jiawei Gu

Creative Commons License

This is an open access article under the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) License.