I am estimating demand elasticities using panel data and I am using effect model in Gretl. I suspect that the independent and dependent variables are correlated due to a simulataneous equation bias. Is there a simple test for autocorrelation I can run? For whatever reason, the DW test option is not available for this model. Thanks so much for your help! Dr. Sam Hakim Pepperdine University Graziadio School of Business and Management (626) 233-1009 sam.hakim@pepperdine.edu<mailto:sam.hakim@pepperdine.edu>