Impact of air pollution on short-term movements: evidence from air travels in China

While there is abundant evidence demonstrating that residents permanently migrate in search of locations with cleaner air, there are considerably fewer studies that investigate if travellers also take short-term trips to reduce their exposure to air pollution. In this study, we use a complete dataset of flights at Beijing International Airport to investigate if travel patterns are indeed correlated with air quality-differences across cities in China. Our identification strategy is aided by instrumenting air quality using thermal inversions. We find that a one-unit increase in the Air Pollution Index of origin over destination city would lead to a 0.36% increase in number of passengers on the flight. When considered separately by cabin-class, the number of first-class passengers increased about three-times faster than economy-class. Using lagged air quality information, we also find that averting-related travel decisions are most sensitive to destination’s air quality on day-of-travel. This indicates that flight passengers likely rely on air quality forecast information to make air pollution-induced travel decisions.