Approximation formulae are developed for the bias of ordinary andgeneralized Least Squares Dummy Variable (LSDV … proper modelling of thedisturbance covariance structure is indispensable. The biasapproximations are used to construct bias … plausible long-run effects are obtained by the biascorrected estimators. Moreover, bias correction can be substantialunderlining …

properties; it explains why standard tests fail to detect bias; and it provides a mechanism for potentially improving forecasts …