Hello,

I am running a ZINB on a pooled panel using the vce (cluster ID) option, yet I have been advised to use the Panel data Model "xtpoisson" or "xtnbreg".

My DV is "panel applications", so I have lots of zeroes while my IVs are some R&D related inputs. I have a large N while T = 4. I am testing my model on both a balanced and unbalanced panel.

I have a couple of questions regarding this:

Is running a ZINB or an NBREG on the pooled panel a bad idea ? Why is that?

I read that using a FE when N is large while T is fixed (or small) is not the best approach. I ran a Hausman test to compare the FE and RE model, and it showed that the FE model is a better choice. Yet, the RE model is giving expected results that are similar to other models I have tested using ZINB and NBREG. Are there any other tests I can run to test for this ?

Do you recommend any other models ? I know that there is no xtzinb or an xtnbreg.

Thanks!