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Re: st: xtmixed with nonrtolerance. What happens?


From   Anders Alexandersson <andersalex@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: xtmixed with nonrtolerance. What happens?
Date   Thu, 23 Jun 2011 17:30:29 -0400

Lukas, I am not an expert. But I do not think that scaling is the
reason for non-convergence since you standardized all variables.
Your model is nearly unidentified, since you get convergence only by
adding the option nonrtolerance.
Could the reason be lots of missing data in the variables that you use
in the model?
For example, what is the result of -xtdescribe-?

Anders Alexandersson
andersalex@gmail.com


On Thu, Jun 23, 2011 at 4:40 PM, "Lukas Bösch" <L.Boesch@gmx.de> wrote:
> Because i didnt transform the year and the export, named as quantity, into z-scores they kept their original names in the first models.
> I just did the transformation and ran the model again, but it still doesnt converge, however seems to work a little better.
>
> . xtmixed centquantity2 centyear2 centforestarea2 centgdp2 centlandarea2 centpopulation2|| _all: R.country || _all: R.genus
> [...]
> In total 40 countries, 213 genus and 21 independendt variables over a period of 16 years with 6192 observations. As there is no hirarchical structure, there are no different levels. There is one level for the quantity exported and two randome effects at this level, the country and genus.
> After having transformed the quantity to z-scores, would you still recommend dividing it by 100k?
>
> Thank you
>
> Lukas
>
>
> -------- Original-Nachricht --------
>> Datum: Thu, 23 Jun 2011 14:41:44 -0400
>> Von: Joerg Luedicke <joerg.luedicke@gmail.com>
>> An: statalist@hsphsun2.harvard.edu
>> Betreff: Re: st: xtmixed with nonrtolerance. What happens?
>
>> k stands for 1000 (as in kb=1000 bytes, for instance). What are your
>> Level 1 observations (i.e., the  6192)? If only 72 bears were exported
>> from the US in a given year then figures in the ballpark of hundreds
>> of thousands appear fairly high to me?
>>
>> J.

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