Is the sky of smart city bluer? Evidence from satellite monitoring data

How to win the "Blue Sky Protection Campaign" is becoming the focus all over the world, especially in developing economies, while the implementation of the smart cities initiative (SCI) is seen to be a feasible program to address the negative environmental externalities through Information and Communication Technologies (ICTs), but it lacks the quantitative evidence so far. This study aims to examine the impacts and potential mechanisms of SCI on air pollution governance from the objective satellite monitoring data within a quasi-natural experiment framework. We find that SCI directly reduces the air pollutants concentration such as PM2.5, SO₂, NO₂, and smog in urban China and improves the air quality very well, which also has significant and positive spillovers on air pollution governance in adjacent cities. This encouraging phenomenon can also be achieved through contributing to green technological innovation, industrial structure upgrading, and decentralizing urban spatial structure, such that most of can be attributed to the technological effect. Heterogeneity analyses demonstrate that the governance effect of air pollution is more obvious in large smart cities, and increases with the expansion of city size. Additionally, the effect performs better in resource-based smart cities and smart cities with stronger financing capacity and air pollution pressure.