Discussion Paper Series

Discussion Paper 109

Issued February 2007

Multiple Inference and Gender Differences in the Effects of Preschool: A Reevaluation of the Abecedarian Perry Preschool and Early Training Projects

Michael Anderson, Universiy of California–Berkeley

Abstract

The view that the returns to public educational investments are highest for early childhood interventions stems primarily from several influential randomized trials—Abecedarian, Perry, and the Early Training Project—that point to super-normal returns to preschool interventions. This paper implements a unified statistical framework to present a de novo analysis of these experiments, focusing on two core issues that have received little attention in previous analyses: treatment effect heterogeneity by gender and over-rejection of the null hypothesis due to multiple inference. The primary finding of this reanalysis is that girls garnered substantial short-and long-term benefits from the interventions. However, there were no significant long-term benefits for boys. These conclusions would not be apparent when using “naive” estimators that do not adjust for multiple inference.

Michael Anderson
Department of Agricultural and Resource Economics
207 Giannini Hall #3310
University of California Berkeley, CA 94720-3310
mlanderson@berkeley.edu

The views expressed herein are those of the author(s) and do not necessarily reflect the views of the Early Childhood Research Collaborative.

Paper [PDF]