Can iron-fortified salt control anemia? Evidence from two experiments in rural Bihar

Iron deficiency anemia is frequent among the poor worldwide. While it can be prevented with the appropriate supplement or food fortification, these programs struggle to reach the poorest, out-of-school children, men and the elderly. This paper reports on the impact of a potential strategy to address iron deficiency anemia in rural areas: salt fortified with iron and iodine (DFS). We conduct a large-scale experiment in 400 villages in Bihar to test the impacts of both selling DFS and giving it away for free. At baseline, 45% of the sample is anemic. In 200 randomly assigned villages, we introduce DFS for the first time at half the normal retail price and sell it for roughly 30 months. In 62 of those sales villages, we deliver DFS for free directly to 7 randomly assigned households over nearly 24 months. We find no evidence that either selling DFS or providing it for free has an economically meaningful or statistically significant impact on hemoglobin, anemia, physical health, cognition or mental health. For the sales experiment, we can reject a reduction of 2.4 percent in the fraction anemic in the entire sample and 1 percent among those who were previously anemic. Using an IV strategy, we find a statistically significant, though relatively small, increase in hemoglobin and reduction in the fraction anemic for adolescents, a subgroup that responded well to supplements and fortification in earlier studies. These disappointing results are explained both by modest purchases and low impact of DFS for the majority of the population, even when consumed somewhat regularly.