National leaders' visits and temporary improvement of air quality: evidence from Chinese cities

In China, during certain politically sensitive periods, there are increased incentives for local officials to prioritize environmental protection over economic growth, resulting in the phenomenon of temporary "political blue sky." This study investigates the relationship between national leaders' visits and air quality, using the Air Quality Index (AQI), individual pollutant data and Chinese President Xi Jinping's visits to cities during November 2013 and May 2017. The results show that AQI begins to drop around 20 days prior to Xi's visits. Nevertheless, this improvement of air quality is only temporary-after visits, air quality quickly deteriorates to usual conditions. Moreover, the improved air quality before visits is primarily contributed by decreases in particulate matter of PM2.5 and PM10, which receive more attention from both government and public than other pollutants do, while other pollutants show no obvious changes. The analysis of Premier Li Keqiang's visits also yields similar results, with less significant influence though.