Analysis of the impact of child health and nutrition on subsequent school performance is hampered by many difficulties. Research using retrospective data is complicated by the possibility that unobserved factors may determine both nutrition and education outcomes, which will generate correlation between these two outcomes that is not necessarily causal. Randomized trials offer a clearer method for identifying causal relationships, but they are relatively rare and encounter several difficulties in practice. This paper examines theory, estimation strategies, and recent empirical evidence to assess the current state of knowledge on the impact of child health and nutrition on education outcomes in developing countries.

We evaluate the impact of a large-scale teacher coaching program, in a context of high teacher turnover, on teachers' pedagogical skills. Previous studies find that small-scale coaching programs can improve teaching of reading and science in developing countries. However, scaling up can reduce programs' effectiveness, and teacher turnover can erode compliance and cause spillovers onto non-program schools. We develop a framework that defines different treatment effects when teacher turnover is present, and explains which effects can be estimated. We evaluate a Peruvian teacher coaching program, exploiting random assignment of that program's expansion to 3,795 rural schools in 2016. After two years, teachers assigned to the program increased their aggregate pedagogical skills by 0.20 standard deviations. The program also increased student learning, and the schools whose teachers' pedagogical skills increase the most are also the schools with the highest increases in learning, indicating that pedagogical skills are one mechanism linking teacher coaching to student learning.