“…Results concerning stationarity, consistency of maximum likelihood (ML) estimates, geometric ergodicity, ‐structure, filtering, duality and statistical inference of univariate MS GARCH models can be found in Francq et al (2001), Francq and Zakoïan (2005), Liu (2006), Abramson and Cohen (2007), Xie (2009), Bauwens et al (2010), Billio and Cavicchioli (2017), and Augustyniak et al (2018). Francq and Zakoïan (2008) describe a procedure for computing the autocovariances and the ARMA representations of the squares, and higher‐order powers, of univariate MS GARCH models, with applications to statistical inference.…”