Hi All,

I am trying to run a bilateral trade gravity model using PPML and trying to control for country-pair fixed effects. I am trying to control for country-pair fixed effects by introducing country-pair dummies in the PPML. I am using the following commands to create the country-pair dummies.

egen pair=group(exporter importer)
tab pair, gen(pair_dum)

However, I am receiving an error message stating that there are too many values. I would really appreciate if you could please help me to solve this problem.

Thanks
Bibhu