Zusammenfassung:
This paper analyses trends and persistence in atmospheric pollution in ten US cities over the period from January 2014 to January 2024 using fractional integration methods. The results support the hypothesis of long memory and mean reversion in atmospheric pollution in all cities examined. They also indicate that Boston is the only city in the sample where atmospheric pollution exhibits a significant positive linear trend, though it is also characterised by the lowest degree of integration, which implies that shocks have transitory effects and mean reversion occurs at a fast rate.