Hi. I am doing a logistic regression. One of my independent variables V is categorical with values 0, 1, 2, 3. The model creates variables V1, V2, V3.
- I understand the meaning of the value of the parameter estimate β1 for V1 as the increase in the odds ratio by a factor of exp( β1). Is this correct?
- Is the meaning of the value of the parameter estimate β2 for V2 as the additional increase in the odds ratio by a factor of exp( β2), over and above exp( β1)? Is this correct?
- Is the meaning of the value of the parameter estimate β3 for V3 as the addidtional increase of the odds ratio ovre and above exp( β2)? Is this correct?
- Suppose the parameter estimate β3 for V3 is significant as measured by its z value, but parameters β1 and β2 are not significant. Does it make sense to eliminate V1 and V2 from the regression, or is something lost by doing so?
Thank you