Improving child health and cognition: Evidence from a school-based nutrition intervention in India

Access to better nutrition in children is crucial for human capital formation and human welfare, especially in developing countries, where 40% of the children are stunted and suffer from chronic under nutrition. While several technologies and product fortification have been used to improve micro-nutrient malnutrition among children, the empirical evidence on the effectiveness of different strategies to deliver micro-nutrients is mixed and unclear. Providing subsidized double fortified salt (DFS), salt fortified with iron and iodine, through village shops failed to improve nutritional and cognitive outcomes in India (Banerjee, Barnhardt, Duflo, 2018). Instead of market institutions, this paper tests the effectiveness of non-market institutions, school lunch programs, in delivering micro-nutrients to school children and examines the short-run impacts of DFS on child health, learning outcomes, and educational attainment in rural India.

In particular, we present experimental evidence on the impact of delivering double-fortified salt (DFS), salt fortified with iron and iodine, through the Indian school-feeding program called “midday meal” (MDM) on anemia, cognition, and math and reading outcomes of primary school children. We conducted a field experiment that randomly provided a one-year supply of DFS at a subsidized price to 2000 students at 104 public primary schools in one of the poorest regions of India. The DFS treatment had significantly positive impacts on hemoglobin levels and reduced the prevalence of any form of anemia by 9.3 percentage points (or about 20 percent) but these health gains did not translate into statistically significant impacts on cognition and test scores. While exploring the heterogeneity in effects, we find that treatment had statistically significant gains in anemia and test scores among children with higher treatment compliance. We find positive treatment effects of 0.2 standard deviations on math and reading scores in the subgroup of students with school-attendance above 80 or 90 percent, who consumed the MDM more frequently at school and therefore had a stronger exposure to the treatment. We further estimate that the intervention was very cost effective and can potentially be scaled up rather easily.

To the best of our knowledge, this is the first large-scale study that rigorously evaluates the usage of salt as an iron carrier in a school-feeding program in India. Furthermore, in contrast to existing studies, we assess not only health but also productive outcomes such as cognitive abilities and education outcomes.