Princeton University, USA.
Northern Arizona University, USA.
Soc Sci Res. 2020 Feb;86:102389. doi: 10.1016/j.ssresearch.2019.102389. Epub 2019 Nov 16.
The 1962-67 High/Scope Perry Preschool Program, a well-known experimental early childhood intervention study that provided quality preschool education to disadvantaged children, has been shown to have had positive impacts on early child development and on a variety of adulthood outcomes. However, most previous analyses have only examined average treatment effects across all program participants without exploring possible effect heterogeneity by children's background characteristics. We investigated this question by first using the 1964-65 Current Population Survey data in combination with the Perry data to construct a scale of child socioeconomic status based on the estimated propensity for inclusion in the Perry program, then analyzing effect heterogeneity within the Perry sample by strata of our socioeconomic scale. We found that the treatment effects of enrollment in the Perry preschool on cognitive and non-cognitive skills were much larger and more persistent among the most disadvantaged children than among others in the Perry program. Furthermore, among the most disadvantaged children, the treatment (i.e., preschool enrollment) affects later outcomes through a reinforcement mechanism of skill development (i.e., early cognitive gain leads to a non-cognitive gain, which in turn leads to later cognitive gain) and a sequential improvement of cognitive skills over time. These findings have important implications for the evaluation of policy interventions in early child development using experimental data.
1962-67 年高/视野佩里学前教育计划是一项著名的实验性幼儿期干预研究，为处境不利的儿童提供优质的学前教育，已被证明对幼儿发展和各种成年后结果有积极影响。然而，大多数先前的分析仅考察了所有参与计划的参与者的平均治疗效果，而没有探讨儿童背景特征可能存在的治疗效果异质性。我们通过首先使用 1964-65 年当前人口调查数据与佩里数据相结合，基于参与佩里计划的估计倾向构建了儿童社会经济地位的衡量标准，然后根据我们的社会经济规模的分层分析了佩里样本中的治疗效果异质性。我们发现，与佩里计划中的其他人相比，参加佩里学前教育对最不利儿童的认知和非认知技能的影响更大且更持久。此外，在最不利的儿童中，治疗（即学前教育入学）通过技能发展的强化机制（即早期认知收益导致非认知收益，进而导致后期认知收益）和认知技能随时间的顺序提高来影响后期结果。这些发现对于使用实验数据评估幼儿发展政策干预的效果具有重要意义。
