Date: Sun, 3 Feb 2008 20:00:23 -0800
Reply-To: Daniel Nordlund <res90sx5@VERIZON.NET>
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From: Daniel Nordlund <res90sx5@VERIZON.NET>
Subject: Re: logistic regression
In-Reply-To: <47A60CD6.404@csulb.edu>
Content-type: text/plain; charset=utf-8
> -----Original Message-----
> From: SAS(r) Discussion [mailto:SAS-L@LISTSERV.UGA.EDU] On Behalf Of Dennis
> G. Fisher, Ph.d.
> Sent: Sunday, February 03, 2008 10:50 AM
> To: SAS-L@LISTSERV.UGA.EDU
> Subject: logistic regression
>
> Are the "parameter estimates" that SAS prints in PROC LOGISTIC
> considered raw (reported as B's) or standardized (reported as betas)?
> Is there any option to convert whatever it prints into the other?
> Pampel (2000) says on page 32 of his book "...logistic regression
> programs do not routinely compute standardized coefficients." However,
> on page 33 he says "SAS prints standardized coefficients for logistic
> regression." However, he continues to criticize the way that SAS
> calculates these standardized coefficients because SAS uses the same
> standard deviation, 1.8138, for all variables. I have not been able to
> find this in the documentation yet. If someone knows exactly where to
> look in the documentation to clarify this, I would appreciate their
> pointing it out. I am trying to figure out how to report these
> parameter estimates correctly, whether as B's or as beta's. TIA
> Dennis Fisher
>
> --
> Dennis G. Fisher, Ph.D.
> Professor and Director
> Center for Behavioral Research and Services
> California State University, Long Beach
> 1090 Atlantic Avenue
> Long Beach, California 90813
> 562-495-2330 x121
> 562-983-1421 fax
> www.csulb.edu/centers/cbrs
As I understand the concept, SAS reports raw coefficients. The reported coefficient for a variable is the change in log(odds) based on a one unit change (in the original scale) of the variable of interest. Out of curiosity, what is your interest in standardized coefficients?
Hope this is helpful,
Dan
Daniel Nordlund
Bothell, WA USA
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