Run away? Air pollution and emigration interests in China

This paper investigates the impact of air pollution on people's interest in emigration. Using an online search index on "emigration" which is positively correlated with its search volume, we develop a city-by-day measurement of people's emigration sentiment. We find that searches on "emigration" will grow by approximately 2.3-4.8% the next day if today's air quality index (AQI) is increased by 100 points. In addition, such an effect is more pronounced when the AQI level is above 200, a sign of "heavily polluted" and "severely polluted" days. We also find that such effect differs by destination countries and by metropolitan areas.