I want to run the Pseudo-Poisson Maximum Likelihood (PPML) in a panel data framework as my dependent variable has many zeroes. However, my challenge is that from all the literature I have read on the PPML, it seems to only work in gravity model type of estimation.
1. Is it possible to run a PPML using panel data for a non-gravity type of model?
2. If it is possible, what is the STATA command to use?