Is my ARMAX model legit?
Posted: Tue Jul 10, 2012 10:39 am
Hi,
I have a task where I'll be modelling outflow in a savings product with respect to a number of explanatory variables through time. I went with an OLS-ARMA approach. There is autocorrelation in the errors, an AR(1) term was able to account for it. Furthermore, a number of these explanatory variables are lagged. I decided to put it in EViews to see what results would be like quickly, before I tried out-of-sample forecasting in MATLAB.
The results that I was seeing in EViews, with respect to the model itself and some dynamic forecasts looked promising. However, when I decided to read up more before trying to program some forecasts in MATLAB, it quickly became clear that these types of models (OLS with ARMA errors, particularly with lagged explanatory variables) are very tricky to do right. Now I tried to make sure that my variables were not correlated, but I assume there is a whole lot more I am missing. I would like to know is making a model like this feasible for someone not that experienced like me, and are the results I would have obtained likely to be correct or are they probably misleading and wrong?
I have a task where I'll be modelling outflow in a savings product with respect to a number of explanatory variables through time. I went with an OLS-ARMA approach. There is autocorrelation in the errors, an AR(1) term was able to account for it. Furthermore, a number of these explanatory variables are lagged. I decided to put it in EViews to see what results would be like quickly, before I tried out-of-sample forecasting in MATLAB.
The results that I was seeing in EViews, with respect to the model itself and some dynamic forecasts looked promising. However, when I decided to read up more before trying to program some forecasts in MATLAB, it quickly became clear that these types of models (OLS with ARMA errors, particularly with lagged explanatory variables) are very tricky to do right. Now I tried to make sure that my variables were not correlated, but I assume there is a whole lot more I am missing. I would like to know is making a model like this feasible for someone not that experienced like me, and are the results I would have obtained likely to be correct or are they probably misleading and wrong?