Abstract: Iron-deficiency anemia is among the world's most widespread health problems, especially for children, but it is rarely studied by economists. This paper evaluates the impact of a health intervention delivering iron supplementation and deworming drugs to 2-6 year old children through an existing pre-school network in the slums of Delhi, India. At baseline 69 percent of sample children were anemic and 30 percent had intestinal worm infections. Sample pre-schools were randomly divided into groups and gradually phased into treatment. Weight increased significantly among assisted children, and pre-school participation rates rose sharply by 5.8 percentage points -a reduction of one-fifth in school absenteeism -in the first five months of the program. Gains are largest in low socio-economic status areas. Year two estimates are similar, but two methodological problems -sample attrition, and the non-random sorting of new child cohorts into treatment groups -complicate interpretation of the later results
