Dynamics of Child Development: Analysis of a Longitudinal Cohort in a Very Low Income Country
研究了马达加斯加儿童在3-6岁和7-10岁两个阶段的认知发展轨迹，发现财富差距在多个认知领域显著存在，随年龄增长而扩大，并在9-10岁趋于平缓，家庭刺激解释了12-18%的早期发展差距。
Longitudinal patterns of child development and socioeconomic status are described for a cohort of children in Madagascar surveyed when 3–6 and 7–10 years old. Substantial wealth gradients were found across multiple domains: receptive vocabulary, cognition, sustained attention, and working memory. The results are robust to the inclusion of lagged outcomes, maternal endowments, measures of child health, and home stimulation. Wealth gradients are significant at ages 3–4, widen with age, and flatten out by ages 9–10. For vocabulary and sustained attention, the gradient grows steadily between ages three and six; for cognitive composite and memory of phrases, the gradient widens later (ages 7–8) before flattening out. These gaps in cognitive outcomes translate into equally sizeable gaps in learning outcomes. 12–18% of the predicted gap in early outcomes is accounted for by differences in home stimulation, even after controlling for maternal education and endowments.