I am working with a data set of roughly 1,500 obs. The model I built is a double-log GLM model to estimate price elasticities. During testing, I discovered the residuals and the dependent variable are strongly negatively correlated (0.85). Of note, the residuals are not correlated with the independent variables.
I have scoured econometrics and statistics textbooks and the only thing I can surmise is the model is misspecified in the functional form or there's an omitted variable. Do either of these make sense?