Self-Protection Investment Exacerbates Air Pollution Exposure Inequality in China

Income inequality is rising in China at the same time that urban air pollution remains high. Households can purchase market products such as masks and air filters to protect themselves from pollution. Using a unique data set of Internet purchases, we document that households invest more in such products when ambient pollution levels exceed key alert thresholds. Richer people are more likely to invest in these products. By combining several existing pieces of research, we provide an estimate of the differential exposure to pollution between rich and poor people in urban China. This differential has implications for life expectancy across groups and suggests that quality of life inequality exceeds cross-sectional measures of income inequality. Significance Statement Urban air pollution remains high in China. During hazy days, Chinese urbanites wear masks outdoors and use air filters indoors to protect themselves against the dirty air. Using a unique data set of Internet purchases, we find that people buy more masks and filters when local air pollution is higher. Richer people are more likely to invest in such self-protection products. By combining several pieces of information, we estimate that the poor inhale more PM2.5, and this shortens their life expectancy relative to richer individuals. This differential is due to differential self-protection investments. We conclude that in China’s cities today that quality of life inequality exceeds income inequality.