The nutritional value of toilets: How much international variation in child height can sanitation explain?
Author: Dean Spears
Published in: World Bank policy research working paper
Physical height is an important economic variable reflecting health and human capital. Puzzlingly, however, differences in average height across developing countries are not well explained by differences in wealth. In particular, children in India are shorter, on average, than children in Africa who are poorer, on average, a paradox called "the Asian enigma" which has received much attention from economists. Could toilets help children grow tall, while disease externalities from poor sanitation keep children from reaching their height potentials?
This paper provides the first identification of a quantitatively important gradient between child height and sanitation, which can statistically explain a large fraction of international height differences. I apply three complementary empirical strategies to identify the association between sanitation and child height: country-level regressions across 140 country-years in 65 developing countries; within-country analysis of differences over time within Indian districts; and econometric decomposition of the India-Africa height difference in child-level data.
The effect of sanitation on human capital is quantitatively robustly estimated across these strategies, and does not merely reflect wealth or other dimensions of development. Open defecation, which is exceptionally widespread in India, can account for much or all of the excess stunting in India.