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From |
"Nick Cox" <n.j.cox@durham.ac.uk> |

To |
<statalist@hsphsun2.harvard.edu> |

Subject |
RE: st: RE: Dropping var from log reg due to estimability |

Date |
Mon, 2 Mar 2009 10:57:47 -0000 |

I don't have the context you have to be able to add anything that isn't obvious. Being "significant" on its own is no guarantee that a predictor belongs in a model. That's why you are doing what you are. Otherwise my only tip is to avoid stepwise like the plague, given the reasons often rehearsed on this list. Nick n.j.cox@durham.ac.uk Ziad El-Khatib Thank you and sorry for the unclear question. Meant to: 1) know what does it mean in this case and 2) how to deal with it? You have kindly answered on point 1. > The underlying reason is likely to be that you are throwing far too many > predictors at the response. --> i added predictors with statistically significant value after doing Adj. OR (2x2 table). On Mon, Mar 2, 2009 at 12:44 PM, Nick Cox <n.j.cox@durham.ac.uk> wrote: > I'm not clear what kind of answer you expect. > > "estimability" means being estimatable, or here strictly being _not_ > estimatable. At its simplest, the signal is thus that -logistic- found > it too difficult to estimate the parameters in the model you specified. > > The underlying reason is likely to be that you are throwing far too many > predictors at the response. > > Nick > n.j.cox@durham.ac.uk > > Ziad El-Khatib > > Using -stepwise, pr(.20): logistic- I ran different variables (all of > them and dependent variables were dichotomous); got the text below > then got the rest in the model. Any tips what does estimability mean? > > > note: incomenone dropped because of estimability > note: awaycat dropped because of estimability > note: busycat dropped because of estimability > note: elsetoseecat dropped because of estimability > note: dailyroutinecat dropped because of estimability > note: depressedcat dropped because of estimability > note: othercat dropped because of estimability > note: incomeself dropped because of estimability > note: 42 obs. dropped because of estimability * * 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**:**st: Dropping var from log reg due to estimability***From:*Ziad El-Khatib <ziad.khatib@gmail.com>

**st: RE: Dropping var from log reg due to estimability***From:*"Nick Cox" <n.j.cox@durham.ac.uk>

**Re: st: RE: Dropping var from log reg due to estimability***From:*Ziad El-Khatib <ziad.khatib@gmail.com>

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