The Impact of Clean Water on Infant Mortality: Evidence from China
Abstract
This study is the first national research on clean water and infant health in China. We have compiled what is to our knowledge the most comprehensive assessment of clean water access, infant mortality, and surface water quality in China ever assembled. By combining these three data sets, we are able to examine an accurate sample of infant mortality and clean drinking water at a level of quality rarely found in developing countries.To address the endogeneity concerns of piped water coverage, we construct a novel instrumental variable based on the least-cost route from water sources to destinations using GIS network analysis. Because construction costs of water pipelines depend critically on the geographical characteristics between a mortality surveillance area and its nearby clean water sources (e.g. reservoirs), we can use the least-cost distance between them as the instrument for piped water coverage. Since the least-cost path is constructed purely based on cost considerations, it should be uncorrelated with demand-side determinants of infant mortality (such as income and social preferences).
We find that provision of piped water significantly decreases infant mortality with a 10 percentage-point increase in piped water reducing infant mortality by 16 percent. Combining surface water pollution and piped water coverage, we find that the effect of piped water provision is greater in regions with slightly polluted surface water rather than in regions with severely polluted water. This counter-intuitive result can be attributed to people’s avoidance behavior: people continue to use slightly polluted water while they avoid visually polluted water. We also show that the economic benefits of piped water in rural China are significantly greater than the estimated costs of its provision.