Childhood stunting and cognitive effects of water and sanitation in Indonesia

•Improved household sanitation reduces childhood stunting by 5 percentage points.•The full benefits of WASH are only realized as sanitation becomes universal.•Cognitive test scores are adversely affected by open defecation. Close to 100 million Indonesians lack access to improved sanitation, while 33 million live without improved drinking water. Indonesia is home to the second largest number of open defecators in the world, behind India. Repeated exposure to fecal pathogens, especially common in areas where open defecation is practiced, can cause poor absorption and nutrient loss through diarrhea and poor gut function, leading to undernutrition, growth stunting and irreversible impairment of health, development, learning and earnings – the effects of which outlast a lifetime. Using data from a sample of over six thousand children in the Indonesia Family Life Survey (IFLS), a household socioeconomic panel representative of over 80 percent of the Indonesian population, we examine the relationship between poor household and community water and sanitation services and childhood stunting and cognitive development. We find that children living in households that have access to improved sanitation when they are under 2 years of age are approximately 5 percentage points less likely to end up being stunted. Community rates of sanitation are also important. Children living in open defecation free communities during this critical development window are more than 10 percentage points less likely to be stunted, than children in communities where all other households defecate in the open. Further, cognitive test scores are adversely affected by open defecation. These findings suggest that owning a toilet and living in a community where most of one’s neighbors own a toilet are important drivers of child growth and development.