The system GMM estimator for dynamic panel data models combines moment conditions for the model in first differences with moment conditions for the model in levels. It has been shown to improve on the GMM estimator in the first differenced model in terms of bias and root mean squared error....

This discussion paper has led to a publication in <a href="http://www.sciencedirect.com/science/article/pii/S0165176511002242">'Economics Letters'</A> 113(1), 76-79.<p> We consider the bias of the 2SLS estimator in the linear instrumental variables regression with one endogenous regressor only. By using asymptotic expansion techniques we approximate 2SLS coefficient estimation...</p></a>