Data Prediction

Dear all,
I have these items for my analysis:
revenue (dependent),
predictors; market share, months.

My point is to estimate revenue for given market share and month to create simulator in excel.

Which SPSS analyze will help to find model and parameters including seasonality?



Not a robit
I am not a times series expert, so I will hold off making a particular recommendation. We can wait and see if any one else chimes in to help.

To my knowledge you would use your coefficients to score future data (months). So perhaps you need to control for months as well. This way you can get values for month name as a categorical variable not just as an ever increasing continuous variable - which I believe would leave you with a straight line instead as a more volatile looking undulating line.
Thank you very much.

I did another analysis with expert models. This is better one.
Does anyone know How to use these parameters in excel formula?