“…Yet, it has been shown that the EM algorithm becomes inefficient in such a low-noise environment (Bermond and Cardoso, 1999;Petersen et al, 2005), causing extremely slow convergence, especially for the factor loading estimates. Unfortunately, this issue seems to have been overlooked by Bańbura and Modugno (2014) and subsequent applications of their approach (see, among others, Coroneo et al, 2016;Scotti, 2016;Alvarez et al, 2016;Bok et al, 2018;Barigozzi and Luciani, 2019;Cascaldi-Garcia et al, 2021;Caruso and Coroneo, 2023). Moreover, these low-noise issues could also arise more naturally whenever the series exhibit a strong factor structure with a high signal-to-noise ratio.…”