Effects of air quality on housing prices: evidence from China’s Huai River policy

Estimating the economic value of clean air is of significance to both policymakers and private individuals but its quantification has proved difficult. Of the different valuation approaches used, the classic hedonic theory predicts a negative relationship between air quality and housing prices. Existing attempts to quantify this nexus is plagued by problems of endogeneity, mainly arising from omitted variables that confound air pollution with other determinants of housing prices. We employ a regression discontinuity (RD) design to estimate the impact of air pollution on house prices across a river that demarcates regions with and without coal-fired heating emanating from the Huai River Policy. This policy was decreed by the Chinese government in the 1950s that allowed burning of coal at subsidised prices for indoor heating to only the north of the Huai River. Employing quasi-experimental variation in particulate matter of 10 micrometres or less in aerodynamic diameter (PM10) generated by this arbitrary policy and regression discontinuity (RD) design based on distance from Huai River, we estimate the local average treatment effect (LATE) to provide new evidence on the capitalization of PM10 air pollution into housing values. By using panel data of 30 large cities on either side of the river for the period 2006 to 2015, we found that 1 μg/m3 reduction in average PM10 results in an approximately 1 percent increase in housing prices. The results are robust to using parametric and nonparametric estimation methods and adjustment to a rich set of covariates.