-2 LL in logistic regression

[Bill Wu]

Can anyone explain why we multiply -2 to log likelihood in regression
analysis output? Is it related to chi square distribution? Any reference
will be appreciated.

Bill

=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD

[SR Millis-3]

When comparing nested models, 2[LL(B)-LL(0)] is distributed as chi square.

Tabachnick & Fidell, Using mutlivariate statistics.



~~~~~~~~~~~
Scott R Millis, PhD, ABPP (CN,CL,RP), CStat, CSci
Professor & Director of Research
Dept of Physical Medicine & Rehabilitation
Dept of Emergency Medicine
Wayne State University School of Medicine
261 Mack Blvd
Detroit, MI 48201
Email:  [hidden email]
Tel: [phone]
Fax: [phone]


--- On Wed, 11/4/09, Bill Wu <[hidden email]> wrote:

> From: Bill Wu <[hidden email]>
> Subject: -2 LL in logistic regression
> To: [hidden email]
> Date: Wednesday, November 4, 2009, 9:56 AM
> Can anyone explain why we multiply -2
> to log likelihood in regression
> analysis output? Is it related to chi square distribution?
> Any reference
> will be appreciated.
>
> Bill
>
> =====================
> To manage your subscription to SPSSX-L, send a message to
> [hidden email]
> (not to SPSSX-L), with no body text except the
> command. To leave the list, send the command
> SIGNOFF SPSSX-L
> For a list of commands to manage subscriptions, send the
> command
> INFO REFCARD
>

=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD