Hi,

If I estimate a gravity model using PPML from a balanced data panel for a several number of countries, but I would like to focus only in one specific country AAA is it the following correct? :


egen exp_time = group(exporter year)
quietly tabulate exp_time, gen(EXPORTER_TIME_FE)

egen imp_time = group(importer year)
quietly tabulate imp_time, gen(IMPORTER_TIME_FE)


ppml TRADE EXPORTER_TIME_FE* IMPORTER_TIME_FE* ln_DIST CNTG LANG CLNY RTA if exporter == "AAA" | importer == "AAA", cluster(DIST)




Or should I drop exporters and importers that are different from country AAA?

Thanks!