Bookmark and Share

Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down at the end of May, and its replacement, statalist.org is already up and running.


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: st: xtmixed with nonrtolerance. What happens?


From   Maarten Buis <maartenlbuis@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: xtmixed with nonrtolerance. What happens?
Date   Fri, 24 Jun 2011 09:31:43 +0200

--- "Lukas Boesch"  wrote:
>> The dependent variable is export. The export of wild animal and plant
>> products from one country to the rest of the world. For example: US export of
>> Bears in 1992: 72.
>> Because I cannot sum up the export of different species to one export
>> figure, obviously bears and pearls are not the same, i have to deal with
>> those mixed models. Socioeconomic factors are set as fixed effects and the
>> genus and countries as the variable effects.
>> As one species can be exported by different countries, the data is not
>> hierarchic and country and genus are cross-classified. Or i think this is
>> what it means. Two random effects at the same level for all observations.

I think that your dependent variable is the main reason why your model
is not converging. It is a count and it will probably suffer from lots
of 0s. In that case I would try using -xtmepoisson-. I suspect it will
still not adequately capture the zeros, but it will be better than the
linear model you used.

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/


© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   Site index