Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down on April 23, and its replacement, statalist.org is already up and running.

# Re: st: Does it need to control industry if the concerned variable has been adjusted by industry?

 From Maarten buis To statalist@hsphsun2.harvard.edu Subject Re: st: Does it need to control industry if the concerned variable has been adjusted by industry? Date Tue, 16 Mar 2010 01:00:33 -0700 (PDT)

```--- On Tue, 16/3/10, gjhxmu@sina.com wrote:
> One variable is characteristic of industry, so I adjust it
> with the median or mean value of industry.
> Then does it need to control industry as regressors if the
> concerned variable is a dependent variable or an independent
> variable?

First, it is not clear what you want to do here. For example,
what did you (want to) type in Stata? Imagine someone who
the substantive issue you want to adjust. However, that person
does know Stata. Imagine what kind of information that person

Second, in statistics you don't _need_ to do anything. There
is no such things as statistical police. Statistics is used
as part of a logical argument that links a question, stuf
you have seen (the data), to an answer. The basic line of
that argument is: I have a question, I have looked around,
this is what I have seen, and it leads to the following
answer. The statistics is just there to summarize the stuff
you have seen, so that it becomes easier to see what the
that you need to do, than it is to just use common sense and
keep this basic line of your argument in the back of your

Third, you cannot add characteristics of an industry _and_
industry dummies. The dummies would absorb all the information
that is available at the industry level, so there is no
information left to estimate the effects of industry
characteristics.

Hope this helps,
Maarten

--------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany

http://www.maartenbuis.nl
--------------------------

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/
```

• References: