Impact of air pollution on short-term movements: evidence from air travels in China[Does the effect of pollution on infant mortality differ between developing and developed countries? Evidence from Mexico City]

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.