Re: st: fractional response using xtgee - correct implementation of random effects and fixed effectst?

[Nick Cox <njcoxstata@gmail.com>]

The 2012 link you give here is to a discussion in 2013.

Otherwise I went to Leslie Papke's home page
http://econ.msu.edu/faculty/papke/ and found a link to Stata code
there.

As a kind of meta-comment it is important to realise that absolutely
no mechanism ensures that Statalist questions will be answered. It is
entirely up to individuals to decide what they wish to answer.

In the particular case of
http://www.stata.com/statalist/archive/2013-06/msg00434.html there
were several helpful replies from Kelvin Mulungu.

But "not answered yet", even when correct,  means no more than it
says. It doesn't mean waiting in a queue.

Nick
njcoxstata@gmail.com

On 4 July 2013 12:23,  <Asmund.Rygh@bi.no> wrote:
> (First line)
>
> Dear Statalist members,
>
> I would like to model the degree of internationalization of firms (a
> fractional variable bounded between 0 and 1) using a strongly balanced
> panel of 30 firms over an 11-year period, and test both the use of fixed
> and of random effects. I am using Stata 12.
>
> I have read Papke and Wooldridge's (2008) article Panel data methods for
> fractional response variables... (see
> http://www.sciencedirect.com/science/article/pii/S030440760800050X) and
> consulted the archives of Statalist. I found one relevant thread from 2012
> at http://www.stata.com/statalist/archive/2013-06/msg00517.html as well as
> a very recent one (last post 12 June) at
> http://www.stata.com/statalist/archive/2013-06/msg00434.html which does
> not appear to have been answered yet.
>
> In the first link from 2012 it is suggested to go to the website of Leslie
> Papke at https://www.msu.edu/~ec/faculty/papke/papke.html where one "would
> find lots of invaluable information with detailed codes as to how
> implement in case of panel data". Perhaps, the answers to my question
> could be found here. However, I am not able to access this site and the
> following message is returned: You don't have permission to access
> /~ec/faculty/papke/papke.html on this server. Thus, my first question is
> simply whether somebody knows if I can access the material in Papke's
> webpage from somewhere else? I have made extensive searches on the web but
> couldn't find anything.
>
> To my main question: From the discussion in the above threads (as well as
> my experience with using random effects and fixed effects in Stata for
> normal variables), I am sort of guessing that the following two commands
> using -xtgee- will achieve what I want:
>
> Random effects: xtgee dependent_variable independent_variables,
> family(binomial) link(logit) vce(robust)
>
> Fixed effects: xtgee dependent_variable independent_variables
> time_averages_independent_variables, family(binomial) link(logit) robust
>
> In the first case, I set firm and year as the panel variables (-xtset-)
> and the output states that the group variable is firm. In the second case,
> which I did not test yet, my interpretation of the discussion in PW2008
> (see p. 123) and at the above mentioned links is that including time
> averages will give me the fixed effects. Is this correct?
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