Project No: 26500016

Title: As the Water Flows: the Effect of Water Pollution on Infant Mortality in China

PI: Prof. He, Guojun   


In the past three and half decades, China has experienced economic growth without historical precedent, with average income rising from $193 per capita to $9,087 (PPP, purchasing power parity). The economic boom, however, has been accompanied by environmental degradation, including a severe deterioration in water quality. According to the World Bank (2007), approximately 70 percent of China’s rivers and lakes were polluted and contained water deemed unsafe for human consumption. However, many poor people in the rural areas still rely on surface water system for daily use, sometimes including drinking. While public concern on the health consequences of this exposure has mounted and significant government resources have been spent to combat the environmental challenge, our understanding of the true health costs of water pollution in China today remains limited and there has been little credible scientific evidence to inform the debate.

The proposed project aims to examine the impacts of water pollution on the health of the most vulnerable group: infants. Specifically, we will address the following empirical questions. First, what are the trends and geographic patterns of water pollution and infant mortality in China in the past decade? Second, does water pollution affect infant health? If yes, how large is the impact? Third, what are the health benefits (in terms of averted infant deaths) if China were to clean the water system (e.g. reduce wastewater discharges)? To do so, we will assemble the most comprehensive data on surface water pollution, wastewater discharges, infant mortality, meteorological and socio-economic conditions for the past decade. We will collect water pollution panel data from both print and electronic sources from the Ministry of Environmental Protection (MEP) and the Ministry of Water Resources (MWR). For infant mortality, we have got access to the Death Surveillance Point System (DSPS) data from the Chinese Center for Disease Control and Prevention (CDC). Beside, we will also collect a rich set of control variables, including socio-economic data from various statistical yearbooks and meteorological data from the over 400 weather stations in China since 1990.

The project will take three steps. First, we will assign an accurate water pollution level to each DSPS location. We match the water pollution data with DSPS locations based on China’s river system and the water basin system. Second, to address the endogeneity issue (nonrandom assignment of pollution levels), we propose a novel instrumental variable (IV) identification strategy based on the upstream-downstream relationship in the river systems. Specifically, we use upstream wastewater discharge and upstream rainfall as instrumental variables for downstream water pollution levels. Arguably, both instrumental variables have a direct impact on downstream surface water quality, but should not affect the health of downstream population except through its impact on water quality. By exploring year-to-year variations in water quality induced by upstream wastewater discharge and rainfall, we can credibly estimate the causal effect of surface water pollution on infant mortality. Finally, we will assess the health benefits of reducing wastewater discharges and offer insights on environmental policy design.

The proposed research is important in economics, environmental science, public health and public policy. We will produce new and important knowledge on the relationship between water pollution and infant mortality in China. Given that the Chinese government has set environmental protection as one of the top priorities in the next twenty years, this study will deepen our understanding of the health costs of water pollution and help policy makers to design efficient policies to address current environmental challenges.