This brief was developed using Microsoft Copilot and edited by Charlotte Sutcliffe, Duke undergraduate research assistant; for full text and references see
Carr, R. C., Watts, T. W., Jenkins, J. M., Bai, Y., Peisner-Feinberg, E., Muschkin, C. G., … Dodge, K. A. (2022). The long-term effect of North Carolina’s pre-kindergarten program is larger in school districts with lower rates of growth in academic achievement. Retrieved from https://doi.org/10.26300/jrgc-8n94
Background:
This study investigates the long-term impact of North Carolina’s state-funded pre-kindergarten (NC Pre-K) program on student academic achievement, specifically examining how the quality of subsequent educational environments influences these effects. Prior research has shown that NC Pre-K improves reading and math outcomes through eighth grade. The current study builds on this by analyzing whether the benefits in funding through average academic achievement and the rate of achievement growth from grades 3 to 8. The study uses an administrative dataset of over one million students born in North Carolina between 1987 and 2005, leveraging variation in NC Pre-K funding across counties and years.
Findings:
The study finds that NC Pre-K funding has a positive, statistically significant effect on student reading and math achievement in eighth grade. These effects are additive to the benefits of attending school districts with higher average achievement levels. However, a key finding is that the positive impact of NC Pre-K is significantly larger in school districts with lower rates of academic growth. This supports the “dynamic substitutability” hypothesis, which suggests that early childhood education can compensate for lower-quality educational environments later in a child’s academic trajectory. In contrast, no significant interaction was found between NC Pre-K and average district achievement, supporting the “additivity” hypothesis - indicating that both early education and subsequent school quality independently contribute to student outcomes.
The study also confirms that average achievement is strongly correlated with socioeconomic status, while achievement growth is more reflective of school-specific contributions to learning. Thus, NC Pre-K appears particularly beneficial for students who later attend schools where academic progress is slower, helping to close achievement gaps.
Takeaways:
Public investments in high-quality early childhood education, such as NC Pre-K, yield long-term academic benefits that are especially pronounced for students in lower-growth school districts. While both early education and subsequent school quality matter, NC Pre-K can serve as a critical buffer against weaker academic environments. These findings highlight the importance of expanding access to early childhood programs and ensuring alignment with K–12 education to sustain and amplify their benefits. Policymakers should consider targeting early education resources toward communities with lower academic growth to maximize long-term impact.