and Farah 2009), particularly language (Noble et al. 2007) and executive function (Farah et al. 2006). Our results show that receptive vocabulary and sustained attention exhibit the largest gradients after the inclusion of lagged outcomes, maternal endowments (education and vocabulary), and home environment. These outcomes also exhibit a steeper widening of the gradient with age, in contrast to the other outcomes.

Next, we assess how much of the wealth gap in child development outcomes could be accounted for by household inputs such as home stimulation. Home stimulation as measured at the time of school age is shown to account for 12-18% of the wealth gap in z-scores across the various domains with the largest findings for receptive vocabulary and memory of phrases, which is a verbal measure of working memory. The estimate represents a lower bound on the role of the home environment as it does not account for the role of lagged home inputs on developmental outcomes.

Finally, the mapping of different domains of child outcomes onto learning outcomes in math and early literacy at school age is documented. The magnitudes of the gap for school learning outcomes are found to map closely with those obtained using our contemporaneous developmental outcomes (sustained attention, receptive vocabulary, and cognitive composite).

The remainder of the paper documents the data and outcomes being studied (section 1), outlines the empirical methods (section 2), describes the results (section 3), and conclusions (section 4).

# II. DATA

This analysis draws from a nationally representative survey of nutrition and child development in Madagascar ( _Enquete Anthropometrique et de Developpement de l’Enfant_ ) that was first administered in 2004. A random subsample of 150 of the original 446 communities representative of all rural and urban areas, excluding the largest urban cities, was drawn for this longitudinal study. About 1,500 children who were ages zero to three years in 2004 were identified for a prospective cohort from these communities (Galasso and Umapathi 2007). Children’s development in multiple domains (including cognitive, language, and executive function) was assessed at two follow-up periods, 2007 and 2011, when the children were three to six years (preschool age) and seven to ten years of age (primary school age). If children changed residence between surveys, they were tracked to different households or villages.

## _Child Development Tests_

The assessments used in this study were specifically selected to focus on the domains that have been shown to be neurologically correlated with poverty or sensitive to nutrition interventions. The choices of which specific tests to use for each domain were based on the adaptability of the tests to the social and cultural realities of Malagasy children and on the practical aspects of their use given the constraints of the investigation (e.g., length of test, sample size, cost and cultural acceptability of materials, and supervision required) (Fernald et al. 2010).

A battery of six cognitive and language tests was administered both in 2007 (Fernald et al. 2011) and 2011<sup>1</sup> ; more detail is provided in appendix S1 (figure S.1 in the supplemental appendix).

> 1. Essential adaptations to the assessment tools were made during the initial development of the battery of tests, followed by adjustments and improvements based on pretest results from the field. No questions were eliminated from any of the child development measures. All instructions and words or phrases were translated into Malagasy and then