I have the two variables with 4 different levels or categories each one (illustrative example):
A1 , A2 , A3 , A4
B1 , B2, B3, B4
I run a logistic regression model and use A1 and B1 as reference group. The point of the research I am conducting is to remove those two "worst" levels per category (remove 2 levels from A and remove 2 levels from B), that is those two levels with smaller coefficient.
Let's say I obtain this parameter estimates:
I don't include the standard errors as they are not necessary for the moment. So given these parameter estimates I remove A3 and B2 because they have the lowest coefficient. But how should I proceed now? A2 and A4 are larger than 0, the reference group. Does this mean that the reference group A1 is worse than the other two A2 and A4 thus it should be removed?
I would appreciate some suggestion on this point!