Why does piped water not reduce diarrhea for children? : evidence from urban Yemen

This paper investigates why household connections to piped water supply can increase diarrheal diseases among under-5-year-old children. Using a unique mix of household data, microbiological test results and spatial information from urban Yemen it is possible to distinguish the adverse impacts of malfunctioning water pipes from unhygienic household behavior on water pollution and health outcomes. The analysis consists of three parts: First, exogenous variation of pipe construction is used to quantify the health impact of access to piped water, which is found to increase the risk of child diarrhea by 4.6 percentage points. Second, by exploiting the spatial correlation of pollution among households connected to the same water pipe, it is shown that broken pipes and interruptions of water supply are responsible for most of the water pollution. Third, unhygienic water storage and handling at household level additionally increases water pollution. These results show for the first time that water rationing can jeopardize the intended health benefits of access to clean drinking water. Importantly, these results apply to most urban areas in Africa and the Middle East where water resources are limited and water supply is frequently interrupted.