I'm developing a linear regression model that contains multiple categorical explanatory variables (e.g., cities, marital status), including other binary and continous variables. The output is 0/1 variable. Later, I will be run through backwards elimination, to pick the best model. My thought was to transform the categorical variables into dummies.
My question is whether I can include all the dummy variables -1 in each category (to avoid the dummy trap). Is this the right way to do it?
Or can I only inlcude 1 of the dummy variables (e.g. New York and Married) from the categorical variable, which I know have significantly high correlation with the output compared to other cities and marital status?