“…As a rule, they do not consider various empirically relevant issues in conjunction, such as: (i) occurrence and the possible endogeneity of regressors additional to the lagged dependent variable, (ii) occurrence of individual effect (non-)stationarity of both the lagged dependent variable and other regressors, (iii) cross-section and/or time-series heteroskedasticity of the idiosyncratic disturbances, and (iv) variation in signal-to-noise ratios and in the relative prominence of individual effects. For example: the simulation results in Arellano and Bover [3], Hahn and Kuersteiner [4], Alvarez and Arellano [5], Hahn et al [6], Kiviet [7], Kruiniger [8], Okui [9], Roodman [10], Hayakawa [11] and Han and Phillips [12] just concern the panel AR(1) model under homoskedasticity. Although an extra regressor is included in the simulation studies in Arellano and Bond [1], Kiviet [13], Bowsher [14], Hsiao et al [15], Bond and Windmeijer [16], Bun and Carree [17,18], Bun and Kiviet [19], Gouriéroux et al [20], Hayakawa [21], Dhaene and Jochmans [22], Flannery and Hankins [23], Everaert [24] and Kripfganz and Schwarz [25], this regressor is (weakly-)exogenous and most experiments just concern homoskedastic disturbances and stationarity regarding the impact of individual effects.…”