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.

• Run away? Air pollution and emigration interests in China