Re: st: update seqlogit

[Maarten buis <maartenbuis@yahoo.co.uk>]

--- On Wed, 10/2/10, Ángel Rodríguez Laso wrote:
> 1) There is a categorical independent variable. Can xi be
> used with -seqlogit-?

yes
 
> 2) One step of the process has three branches instead of
> two (at home, absent, long absence). Can this be modelled with
> -seqlogit-? Is 3 4:5 6 the correct way to define it?

This can be modelled but what you propose is not correct, you
would need to have two colons. Say 4 = "at home", 5 = "absent",
and 6 = "long absent", then you would represent that transition
as 3 4 : 5 : 6. 
 
> 3) It is difficult for me to give levels to the categories.
> Of course, being interviewed is the desired outcome, but I 
> cannot say that it is x times more important that other
> outcomes, as you do in your dissertation. On the other hand,
> these other outcomes would definitely have to have the same
> value.

These values are only necesary for the decomposition of the
effect on the expected outcome into a weighted sum of the 
effects at each transition. If there is not a scale on which
the outcome can be measured, than you can't compute a mean,
so this decomposition would not make sense in that case. 
However you can still estimate a sequential logit, in order
to determine the effects at each transition.
 
> 4) In this example, I try to decompose the effect of the
> variable sex, but I would like to investigate the
> decomposition of the effects of other explanatory variables.
> I suppose I only need to change the other variables for sex
> in ofinterest. I’m interested in the interaction:
> sex*origin and sex*age1 sex*age2 sex*age3. I’ve
> understood that the options ofinterest (sex)
> over(origin age1 age2 age3) generate the interaction terms.

Correct.

Adriaan Hoogendoorn and Jacco Daalmans have recently published 
a similar analysis of response patterns in:
Adriaan Hoogendoorn and Jacco Daalmans (2009) "Nonresponse in 
the Recruitment of an Internet Panel Based on Probability 
Sampling" Survey Research Methods, 3(2):59--72. 

Hope this helps,
Maarten

--------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany

http://www.maartenbuis.nl
--------------------------


      

*
*   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/