Re: st: Problems with Margeff

[Richard Williams <richardwilliams.ndu@gmail.com>]

Assuming you have Stata 11, why don't you use the new margins command 
and see what it gives you?  Older commands tend to give wrong answers 
because they don't know when variables are interdependent, e.g. they 
will plug in a 1 for one of the dummies and mean values for the 
others, when the others should be set to zero. This handout discusses 
the problems with older commands like mfx and adjust when you have 
multiple dummies, interaction terms and squared terms.  Older 
commands also don't let you use the new -asobserved- option which 
many feel is superior to plugging in means in your calculations.

http://www.nd.edu/~rwilliam/xsoc73994/Margins01.pdf

At 07:34 AM 11/1/2010, Neli Demireva wrote:

> Dear Stata Users,
>
> I am looking into migrants' transitions from unemployment to employment.
>
> I am using a mulltinomial logistic regression for this purpose with 
> the following syntax line:
> xi:mlogit activity age agesq  i.famstat i.housing i.isced i.natz 
> i.country i.anyclaim Ldurun Lmethod w1yr  if L1.activity==2 & sex==1 
> [pw=wt], cluster(persid) baseoutcome(1)
>
> Ldurun and Lmethod are lagged variables. The cluster option is 
> needed because individuals are represented with more than one observation.
>
> If I use the 'mfx' command to compute marginal effects, I get 
> different signs of the coefficient and the m.e. estimate. I thought 
> I will use margeff. Neither margeff, nor margeff, percent seem to be 
> working (although I have margeff installed). Only margeff, outcome 
> (2) produces m.e. estimates still different in sign from the coefficients.
>
> Any ideas as to why this is happening and suggestions how to proceed?
>
> With best wishes,
>
> Neli
>
>
>
>
> Dr. Neli Demireva
> Leverhulme Post-Doctoral Researcher
> Nuffield College Research Fellow
> Department of Sociology
> Manor Road
> OX1 3UQ
> Oxford
> Tel: 01865 286177
> http://oxforddiversityproject.weebly.com/neli-demireva.html
> *
> *   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/

-------------------------------------------
Richard Williams, Notre Dame Dept of Sociology
OFFICE: (574)631-6668, (574)631-6463
HOME:   (574)289-5227
EMAIL:  Richard.A.Williams.5@ND.Edu
WWW:    http://www.nd.edu/~rwilliam

*
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*   http://www.ats.ucla.edu/stat/stata/