Prenatal Exposure to Drought and Infant Mortality: Can Access to Groundwater Buffer the  Impacts of Drought in Tanzania

This paper examines whether economically accessible groundwater can mitigate the effects of prenatal drought exposure on infant mortality. We combine geo-referenced Demographic and Health Survey (DHS) data from Tanzania for 1999, 2010, 2015, and 2022 with information on aquifer types from the World Bank’s report "The Hidden Wealth of Nations". We find that each additional month of drought exposure in utero increases infant mortality by 0.4 percentage points, equivalent to a 5\% increase relative to the sample mean. Importantly, this adverse effect is observed only in areas where aquifer characteristics make groundwater extraction economically difficult. No statistically significant effect is found in areas underlain by economically accessible aquifers. These findings indicate that groundwater accessibility may provide an important form of natural protection against early-life climate shocks and support prioritizing sustainable groundwater infrastructure in drought-prone areas where access is currently constrained.