“…They showed that, under nearly non-stationarity and assuming finite second moment for t , the CLS estimator weakly converges to a normal distribution at the rate n 3/2 . Other related works dealing with nearly unstable INAR (Galton-Watson/branching) processes are due to Wei and Winnicki (1990), Winnicki (1991), Ispány, Pap and Van Zuijlen (2005), Rahimov (2007), Rahimov (2008), Drost, Van Den Akker and Werker (2009), Rahimov (2009), Barczy, Ispány and Pap (2011), Ispány, Körmendi and Pap (2014), Barczy, Ispány and Pap (2014), Guo and Zhang (2014), and Barczy, Körmendi and Pap (2016). Practical situations demonstrating evidence of a nearly unstable INAR model are discussed for instance by Hellström (2001).…”