Caporale, Guglielmo Maria; Gil-Alana, Luis A.; … - 2020
, Helsinki, London, Luxembourg, Madrid and Paris) over the period 2014-2020 by applying a fractional integration framework; this …-stationary series used in most other studies on air pollutants. All series are found to be characterised by long memory and fractional … integration, with orders of integration in the range (0, 1), which implies that mean reversion occurs and shocks do not have …