Re: st: RE: mlogit and IV? polychotomous logistic model and endogenousexplanatory variable

[Marcello Pagano <pagano@hsph.harvard.edu>]

If it is good enough for the Oxford English Dictionary,
it is good enough for me:

Divided, or involving division, into many
(or more than two) parts, sections, groups, or branches:
= POLYTOMOUS 
<http://dictionary.oed.com.ezp2.harvard.edu/cgi/crossref?query_type=word&queryword=polychotomous&edition=2e&first=1&max_to_show=10&single=1&sort_type=alpha&xrefed=OED&xrefword=polytomous>. 
So polychotomy, division into more than two
parts or groups, as in classification: = POLYTOMY 
<http://dictionary.oed.com.ezp2.harvard.edu/cgi/crossref?query_type=word&queryword=polychotomous&edition=2e&first=1&max_to_show=10&single=1&sort_type=alpha&xrefed=OED&xrefword=polytomy>.

*1858* MAYNE 
<http://dictionary.oed.com.ezp2.harvard.edu/help/bib/oed2-m2.html#mayne> 
/Expos. Lex./, /Polychotomus/, applied to a body that is
divided into numerous articulations..: polychotomous. *
1887* /Amer. Naturalist/ Oct. 915 Polychotomy is probably never more
than provisional, and all classification will eventually be dichotomous.

So until we eventually reach the dichotomy where some of us
are right and some of us are wrong, let's allow polychotomous.

m.p.

Nick Cox wrote:


> My only advice is marginal to your main question.
>
> The term "polychotomous", although common in the 
> literature, is malformed and based on a misparsing 
> of the word "dichotomous", whose elements 
> are "dicho" and "tomous". The term "polytomous", 
> also common in the literature, is more nearly correct.  
> Help stamp out this linguistic monstrosity! 
> Nick 
> n.j.cox@durham.ac.uk 
> N.B. this is a different kind of argument from 
> those in favour of "heteroskedasticity" rather than 
> "heteroscedasticity". In the latter case, there are 
> plenty of precedents for rendering the Greek letter
> kappa into the English letter c, so one could be 
> sceptical about that argument. 
> "polychotomous" just got into the literature because someone 
> didn't understand the etymology of "dichotomy" and other people 
> copied that mistake. It's still wrong. 
> Ngo,PT, a.k.a. Thi Minh 
>  
>
> > Sorry to bother you again for the second time in the day!
> >
> > I would like estimate a polychotomous logistic model using 
> > mlogit. The main explanatory variable (say X) I use is 
> > endogenous and in binary models, I have used IVs using the 
> > ivprob command. How would one go about estimating 
> > polychotomous logistic model with an endogenous variable for 
> > which I have an instrument? I am interested in getting the 
> > relative risk ratio as I am trying to differentiate the 
> > impact X on the various discrete categories of Y on the left 
> > hand side.
> >
> > Any advice would be really appreciated. It is the first time 
> > I am using logit/probit and
> > polychotomous models.
> >    
> *
> *   For searches and help try:
> *   http://www.stata.com/support/faqs/res/findit.html
> *   http://www.stata.com/support/statalist/faq
> *   http://www.ats.ucla.edu/stat/stata/
>  
*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/