Hi Everyone,

I am performing a Diff-in-diff analysis using an outcome with many zeros in the panel data. For this reason, I need to use the Poisson pseudo-maximum-likelihood estimation. I have searched online, especially on stata forum in order to know how it works on in stata but I didn't find anything regarding this issue.

Would anyone help maybe by sending a good source or by sending the stata code?

This is the regression code I am using at the moment:
Code:
xi: areg MW treatment i.year Grad Bach  business Age Unemp Republic Democrats   Electricity income, absorb(county) vce(cluster county);
Thanks,
Ali