Re: st: restricting margins to significant variables only

[Maarten buis <maartenbuis@yahoo.co.uk>]

--- On Fri, 18/3/11, Richard Williams wrote:
> Having said that, you can always have margins fix some
> variable values at 0. That might make good substantive sense
> in some cases (e.g. you want to make predictions for a group
> coded 0) but I don't see why you would want to do so in this
> case. Indeed, it would be silly to fix a variable at 0 when
> 0 is not a possible or likely value for the variable.

The original question was "Is it advisable to get margins to
base its calculations on only those variables which are
significant?" In that case you do not want to set the variable
to zero but its effect, i.e. a form of stepwise selection, 
which I told him was a bad idea.

-- Maarten

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

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



      

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