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From | Estrella Gomez <estrellastata@gmail.com> |
To | statalist@hsphsun2.harvard.edu |
Subject | st: Time varying fixed effects with xtreg |
Date | Wed, 6 Jul 2011 16:38:38 +0200 |
Dear Statalisters I am trying to estimate a gravity equation for trade that should include time varying fixed effects. I have tried to include a set of dummies for each exporter and year, and another set of dummies for each importer and year. In order to do so, I have first created both sets of dummies using these commands: egen it=group (i t) egen jt=group (j t) where i is the exporter, j is the importer and t is time (yearly) Hence, my regression should be like this: xtreg trade $indepvars i.it i.jt, fe robust The individual of the panel is pair of countries. Hence, the within transformation should drop out all the time invariant country pair specific fixed effects, and the set of dummies should control for all the time varying country specific fixed effects. However, since I have 80 countries and 40 year, Stata does not allow me to run this regression. Does anybody knows an alternative procedure? Thank you very much, Estrella * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/