After I ran a Hausman-test I got informed that I needed to use a fixed model instead of a random model. However, I want to test the effect of a time-invariant variable called Male.

I know that -xtreg, re- combines the effects of -xtreg, be- and -xtreg, fe- and -xtreg, fe- controls for all fixed effects.

-xtreg, re- doesn't control for all random effects if I'm correct

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However when I use -xtreg, be- instead of -xtreg, fe- I don't control for all fixed effects and therefore I would have an omitted variable bias.

Due to my above questions, I'm stuck after searching the Internet for 8.5 hours

I know that -xtreg, re- combines the effects of -xtreg, be- and -xtreg, fe- and -xtreg, fe- controls for all fixed effects.

-xtreg, re- doesn't control for all random effects if I'm correct

"

**xtreg, be**answers the question about the effect of x when x changes between person. This can usefully be compared with the results of**xtreg, fe**, which answers the question about the effect of x when x changes within person. " Based on that I shouldn't use -xtreg, fe- and use -xtreg, be- instead because I want to know the effect of gender (variable Male)However when I use -xtreg, be- instead of -xtreg, fe- I don't control for all fixed effects and therefore I would have an omitted variable bias.

Due to my above questions, I'm stuck after searching the Internet for 8.5 hours

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