sanitation externalities, disease and children’s anemia Diane Coffey Office of Population Research, Princeton University prepared for PAA session on Public Health & Demography, May 2, 2014

what is anemia? hemoglobin: a protein in red blood cells that carries oxygen anemia: lack of hemoglobin ◦ hemoglobin concentration below 11 gm/dL blood (WHO, 2005) in children

why does anemia matter? Scrimshaw, 2000: increased susceptibility to infection Grantham McGregor & Ani, 2001: impaired cognitive ability Walter et al. 1989: impaired physical development Stevens et al., 2011: globally, 43% of children anemic; 58% in South Asia

causes of anemia diet: iron, vitamin B12, folate diseases ◦ intestinal parasites ◦ environmental enteropathy ◦ malaria blood loss

hypothesis

outline background ◦ why is this link plausible? ◦ sanitation externalities empirical results ◦ cross country gradient ◦ cross sectional results from India & Nepal ◦ fixed effects results from Nepal policy implications ◦ does poor sanitation make other interventions less effective?

background

why is this link plausible? diseases caused by open defecation intestinal parasites – feces on the ground spread parasites that enter kids’ bodies by the feet and mouth (Rosenberg & Bowman, 1982) environmental enteropathy – bacteria in feces reduces absorptive capacity of intestines (Walker, 2003; Humphrey, 2009) background

why is this link plausible? open defecation and height growing literature in economics and epidemiology finds effects on height – Bangladesh: Lin et al., 2013 – Indonesia: Cameron et al., 2013 – India: Hammer & Spears, 2012 – international: Spears, 2012 height and hemoglobin could be influenced by similar intestinal diseases background

sanitation externalities Observations are children in India’s 2005 DHS.

empirical results

cross country gradient

data hemoglobin & open defecation: DHS – 81 surveys from 45 countries – 1995 – 2012 – 60% of surveys are from SSA GDP per capita & population density: Penn World Tables & World Bank malaria: WHO incidence estimates (Korenromp, 2005) cross country motivation

R 2 = 0.23 density of open defecation and hemoglobin in 81 DHS R 2 = 0.26

open defecation density and hemoglobin in 81 DHS – net of malaria R 2 = 0.43

regression gradients: density of open defecation & hemoglobin

fixed effects results from Nepal

data Nepal’s Demographic & Health Surveys from 2006 and 2011 – 2006: 4,680 kids 6-59 months – 2011: 2,100 kids 6-59 months 15 percentage point drop in open defecation – 2006: 50% of households – 2011: 35% of households fixed effects results

identification how is change over time in open defecation within 25 regions associated with change in hemoglobin levels in those regions? fixed effects results

change over time in open defecation within Nepali regions predicts change in hemoglobin

policy implications

in India, associations between parasite medicine and hemoglobin and iron pills and hemoglobin are weaker where there is more open defecation difference in hemoglobin levels between kids who took parasite medicine and those who did not difference in hemoglobin levels between kids who took iron pills and those who did not

summary This study adds to a growing body of research that shows the importance of sanitation for nutrition, particularly in South Asia.

This study provides econometric evidence that open defecation may spread diseases that cause anemia. summary

It suggests that efforts to improve anemia by supplementing diets and treating parasites could be importantly complemented by greater attention to sanitation. summary

questions? comments?

the association between parasite medicine and hemoglobin is greater where there is less open defecation difference = 0.4 gm/dL difference = 0.2 gm/dL 10% 90%