Dear all

I am running gravity model for my thesis and trying to include countrypair fixed effects as well as country time fixed effects in my model. I've read instruction here and ran reghdfe command that is reghdfe dependent variable independent variables, absord (i.ex#i.year i.im#i.year) vce cluster (ex#im) where ex is exporter and im is importer. However there was an error "option absord or noabsord required" and I could not get the result as expected. I'm really hopeful for your helps. Thanks in advance!