st: help me please,about Stata

["[gb2312] ����" <hxg@mail.shufe.edu.cn>]

Dear Sir/Madam,

I am trying to do a test in stata using my panel dataset and I keep
getting the following message:
    i () required
    r (198)
    (the command line is xtreg lwage black exper, re)

Then I add the option i(<grp_year>) to the end of the command.(year means from 2001 to 2006),but no matter what I change, I keep getting that message.


Please help

 Thanks

---------------------------------------------
Xiaogang He
Associate Professor and Associate Dean

School of International Business Administration
Shanghai University of Finance and Economics
777 GuoDing Road, Shanghai 200433, China

Tel: 86-21-65903670
Mobile:86-1339114



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