Hello STATA community,

i am running a gravity model with exporter_time_FE, importer_time_FE and country pair fixed effect. I have the following command to do the fixed effects:

egen exp_time = group(exporter year)
tabulate exp_time, generate(EXPORTER_TIME_FE)
egen imp_time = group(importer year)
tabulate imp_time, generate(IMPORTER_TIME_FE)
egen pair_id = group(exporter importer)
tabulate pair_id, generate(PAIR_FE)

As I have 248 countries and 72 years in my data, that means i will have 248*72*2+248*248=97,216 dummy variables created, which should be fine for STATA/MP (with up to 120,000 variables).

However, with the command "tabulate exp_time, generate(EXPORTER_TIME_FE)" as well as "tabulate pair_id, generate(PAIR_FE)" the error message "too many values" occurs every time. I tried to reduce the length of year, and other solutions in the forum (create a loop), but this error message keeps poping up.

I would like to ask the community is there any walkaround to solve this "too many values" problem or if there is another way to do the exporter time fixed effects, importer time fixed effects and country pair fixed effects?

Looking forward to your answers/suggestions! Thanks!

Best Regards,

Zhixiao