Association for Public Policy Analysis & Management

Preschool attendance, as an investment in human capital, can generate substantial private gains in the short- and long-term (Magnuson & Duncan, 2016). The benefits of preschool attendance may spill over directly from students who have preschool experience (“preschool-goers”) to those who do not (“non-preschool-goers”) through daily interaction when they enter formal schooling (Bailey et al., 2017; Dodge et al., 2017; Neidell & Waldfogel, 2010). A classroom with more preschool-goer peers may also serve as a “sustaining environment” for preschool-goers, which supports continuous, intellectually-stimulating learning (Bailey et al., 2017). With ongoing efforts to expand early childhood education programs, knowledge of the spillover effects is important to understand the social returns of early childhood programs and fuel discussions regarding how to sustain preschool gains .

Despite the vast literature on peer effects at all levels of schooling, little attention has been given to the spillover effects of preschool attendance. This study provides the first experimental evidence of the peer effects of preschool attendance on student cognitive and noncognitive outcomes in early adolescence. We exploit the random assignment of students to classrooms upon junior high school entry (7^th grade) in a unique setting, China. Specifically, we examine the effects of having peers who went to preschool in one’s junior high school classroom on student academic performance, cognitive ability, mental health, school engagement, and educational expectation at the end of 7^th grade and 8^th grade. The random assignment eliminates the three common sources of bias in a peer effects investigation – the endogeneity of peer group formation, the reflection problem, and the mechanical relationship between peer and own achievement measures (Angrist, 2014; Manski, 1993).

Another contribution of this study is the exploration of mechanisms. The mechanisms by which preschool-goer peers might affect their classmates have been hypothesized, yet barely tested. Our study extends the literature by testing the inter-student and student-teacher interactions as potential mechanisms. We also explore a relatively new channel – after-school study time – under the hypothesis that the influence of peers may go beyond classroom interaction.

We draw our data from the baseline wave and the 8^th-grade follow-up of the China Education Panel Survey, the first nationally representative survey of junior high students in China. Current analysis on the baseline wave data shows that a higher proportion of preschool-goers in the class is associated with a 0.01 SD increase in academic performance and 0.01 SD increase in educational expectation, although only the effects on educational expectation remain robust after controlling for classroom average peer characteristics.

In terms of mechanisms, we find suggestive evidence for the peer effects operating through improved inter-student interaction but do not find evidence on student-teacher interaction. Notably, after-school study time is the most robust mechanism among the three.

Additionally, we find that the positive effects of preschool-goer peers on academic performance and educational expectation are mostly driven by preschool-goers. Both preschool-goers and non-preschool-goers spend more time on study after school when they have a higher proportion of preschool-goer peers in the class.