Research from the United States shows that gaps in early cognitive and non-cognitive ability appear early in the life cycle. Little is known about this important question for developing countries. This paper provides new evidence of sharp differences in cognitive development by socioeconomic...

This paper documents disparities in cognitive development-as measured by a receptive vocabulary test-between children from households with high and low socioeconomic status (SES) in two different phases of childhood (before and after early school years) in four developing countries: Peru,...

The effects of early life circumstances on cognitive skill formation are important for later human capital development, labor market outcomes and well-being. In this paper, we test the hypothesis that the first 1,000 days are the critical window for both cognitive skill formation and physical...