fixed effects help

[Derin Yigidim]

I need to identify workers working in the same firm and same MSA. I have panel data.

Y=a + b*X + firm*MSA fixed effects (1)

Y=a + b*X + firm_it + MSA_it (2)

The first specification uses time-invariant two-way firm*MSA fixed effects.

The second specification uses time-variant firm (firm_it) and time-variant MSA (MSA_it) fixed effects. Can you *please* tell me which specification identifies workers working in the same firm and same MSA correctly?

[Carlo Lazzaro]

Derin:
if your query in, in fact, a statistical assignment, please note that posting and answering this kind of stuff is discouraged on this forum (especially if the query seems to aim to a simple this/that yes/no reply).
Things might be different if you show what you've tried yourself in Stata (that is, what you typed and what Stata gave you back) via CODE delimiters and ask for an opinion on what you've done. Thanks.