I am working on an assignment where the current model is an OLS model that models the percent change in a variable, X, by regressing it against a bunch of economic variables such as unemployment rate, nominal GDP, HPI, etc.
My questions are:
Should we consider the possibility of non-stationarity and seasonality for the variables, given that the model is OLS? If so, why?
What are the alternatives for modeling such a relationship, time series, or any other?
The data are available for each independent variable and the dependent variable for 10 years for each quarter.