Early-Life Exposure to Tap Water and the Development of Cognitive Skills

We examine the impact of early-life exposure to tap water on children’s cognitive skills in later life. We exploit the variation in the timing of tap water connections across communities imposed by a major drinking water safety program in rural China. Using data extracted from the China Family Panel Studies, we find that one additional year of exposure to tap water in early life increases the cognitive test score at ages 10–15 by 0.132 standard deviations. The event study estimates confirm that the beneficial impacts of tap water exposure are concentrated in early life.