Re: st: two level model

[Viktor Slavtchev <viktor.slavtchev@uni-jena.de>]

Maarten,
first of all thank you very much for your very quick reply.
However, I have an additional question.
Please correct me if I am wrong, but as far as I know, in the McFadden's 
choice model only one option is allowed to be chosen.
That is, everyone goes for only one particular option out of set of many 
options. In other words, if one decides to invest in the US, all the 
money goes to US and nothing can be invested elsewhere.
As to my understanding, it will be equivalent to -mlogit- model or 
better -clogit- if a subset of the covariates is attributed not to the 
particular choice but rather to some individual characteristics.
In my case multiple choice can be made. Is -clogit- in such a case an 
appropriate method?
What do you think of some kind of two-level approach?
And second, it seems to be that -asclogit- is available only in Stata 10.
Since I am working with Stata 9 my question is about the differences 
between the new -asclogit- and the old -clogit-.
According to the Stata manual McFadden's choice model can be estimated 
by means of -clogit-.
warm regards
viktor





Maarten buis wrote:

> Viktor:
> I have only a very partial answer to your question. The situation you
> describe reminds me of what economists call McFadden's choice model,
> -asclogit- in Stata. This has a very similar structure: multiple
> options and the choice between them can be influenced by both
> characteristics of the choice and the individual making the choice. The
> problem is that this model deals with discrete outcomes, and you are
> dealing with proportions. However, finding and understanding a very
> similar model can sometimes be very helpful in solving such problems.
>
> Hope this helps,
> Maarten
>
> --- Viktor Slavtchev <viktor.slavtchev@uni-jena.de> wrote:
>   
> > I have followed model.
> > People can make (multiple) choices. For example, people can invest
> > their money in different countries, whereat multiple investment
> > options are possible at the same time.
> > Some people decide to invest all the money in (say) Germany, other 
> > decide to invest in both Germany and US, third group invests in
> > Germany, US and UK.
> > The decision depends on country specific characteristics and on 
> > individual characteristics.
> > The estimation of the impact of country specific characteristics on
> > the investment decision should be not problem since these
> > characteristics are unique for each country.
> > But how to estimate the impact of individual characteristics on the 
> > investment decision since these are the same for each individual (do
> > not differ with the different countries within one person)?
> > Example
> >
> > id 	country 	investment_share 	interest_rate 	gender
> > 1 	Germany 	.2 	.02 	0
> > 1 	US 	.5 	.03 	0
> > 1 	UK 	.1 	.025 	0
> > 1 	France 	.1 	.022 	0
> > 1 	Italy 	.1 	.023 	0
> > 2 	Germany 	.6 	.02 	1
> > 2 	US 	.1 	.03 	1
> > 2 	UK 	.1 	.025 	1
> > 2 	France 	.1 	.022 	1
> > 2 	Italy 	.1 	.023 	1
> > 3 	Germany 	.2 	.02 	0
> > 3 	US 	.5 	.03 	0
> > 3 	UK 	.1 	.025 	0
> > 3 	France 	.1 	.022 	0
> > 3 	Italy 	.1 	.023 	0
> >
> >
> >
> > I've just tried followed:
> > xi: glm investment_share interest_rate gender i.id, family(binomial) 
> > link(logit) scale(x2)
> >
> > Is this an appropriate way to solve the problem?
> > Or should I use some kind of multilevel approach?
> > Could -xtmixed- be an appropriate method?
> > Or perhaps there is another way?
> > Tanks for any help.
> > best
> > viktor
> >
> >
> >
> > *
> > *   For searches and help try:
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> > *   http://www.ats.ucla.edu/stat/stata/
> >
> >     
>
> -----------------------------------------
> Maarten L. Buis
> Department of Social Research Methodology
> Vrije Universiteit Amsterdam
> Boelelaan 1081
> 1081 HV Amsterdam
> The Netherlands
>
> visiting address:
> Buitenveldertselaan 3 (Metropolitan), room Z434
>
> +31 20 5986715
>
> http://home.fsw.vu.nl/m.buis/
> -----------------------------------------
>
>
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>   
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