t test in panel data

[Naina Grover]

hello there ,
I have an unbalanced panel data of banks comprising of 21 public,42 foreign and 21 private banks.I want to test whether there is a difference in mean profitability of these three groups.I have created dummies for each group as well.How can i test the difference in mean of these groups.
Please help
Thanks in advance

[Naina Grover]

my data is as follows
BANK ID YEAR PROFIT PRIVATEDUMMY PUBLICDUMMY FOREIGNDUMMY
1 2005 20% 1 0 0
1 2006 15% 1 0 0
. . . . . .
2 2005 17% 0 1 0

[Marcos Almeida]

Welcome to the Stata Forum / Statalist.

Please read the FAQ. There you'll find great advice about sharing data/output/command, plus tips on posting a very informative message.

That said, to start, you don't need to create dummies for the categorical variable. Just use the information as a categorical variable. Otherwise, you may think about - test - as a postestimation.

[Naina Grover]

Marcos Almeida sir what kind of postestimation test?

[Marcos Almeida]

I meant the - test - command.

[Naina Grover]

Marcos Almeida sir, Can we apply anova on panel data.I have created categorical variable for my types of banks

[Marcos Almeida]

You may change the reference level. For this, use factor notation, for example, "ib3.catvar". The command - test - can test one level against the other. You may find examples by typing - help test - in the command window, or by checking postestimations within panel data frame,