“…While the estimators proposed for panels with large dimensions have been widely popular, other methods developed for panels with small, or fixed, T have not been frequently adopted by practitioners conducting empirical academic research. One reason, as mentioned in Juodis and Sarafidis (2020) and illustrated in Attanasio, Meghir, and Nix (2020) and Del Bono, Kinsler, and Pavan (2020), is that identification of the factor model requires normalization restrictions that matter for the interpretation of results (Agostinelli and Wiswall, 2016). In some cases identification is achieved through the use of dedicated measurements, where a priori knowledge is used to associate certain measurements uniquely with specific factors (for example a test can be associated uniquely with a given skill e.g.…”