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Re: st: Stata 11 - Factor variables in a regression command
From
Richard Williams <[email protected]>
To
[email protected]
Subject
Re: st: Stata 11 - Factor variables in a regression command
Date
Sat, 01 May 2010 10:58:45 -0500
At 12:27 AM 5/1/2010, Ricardo Basurto-Dávila wrote:
I am having trouble understanding the difference between a regression that
uses a cross operator (#) and one that uses a cross factorial operator (##).
For example, this is the output I get from running two different
regressions:
FYI, here is how the manual explains it. If you
have Stata 11 you should have the manual in PDF
form; see section 11.4.3 of the User Guide.
i.group#i.sex indicators for each combination of
levels of group and sex, a two-way interaction
group#sex same as i.group#i.sex
group##sex same as i.group i.sex group#sex
-------------------------------------------
Richard Williams, Notre Dame Dept of Sociology
OFFICE: (574)631-6668, (574)631-6463
HOME: (574)289-5227
EMAIL: [email protected]
WWW: http://www.nd.edu/~rwilliam
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