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Re: st: How to perform GLM with nested observations


From   "Austin Nichols" <austinnichols@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: How to perform GLM with nested observations
Date   Wed, 23 Jul 2008 12:50:22 -0400

Jeph--
With a depvar that is a count, I think you would prefer -xtmepoisson-
but the cluster option on -glm- or -poisson- is the place to start,
and with 500 sites there are no worries about insufficient clusters.

On Wed, Jul 23, 2008 at 12:33 PM, Jeph Herrin <junk@spandrel.net> wrote:
> See -xtmixed-
>
> K.Boughey@uea.ac.uk wrote:
>>
>> Dear List,
>>
>> I have 500 sites, and each site contains twelve transects.
>>
>> My dependent variable is the number of bats encountered along each
>> transect.
>>
>> My independent variables have been measured at either transect or site
>> level and include:
>> habitat type (categorical) measured at transect level
>> distance to nearest water feature measured at transect level
>> proportion of woodland, measured at site level
>> density of water features, measured at site level
>>
>> Is there a way I can include all 6000 observations and all independent
>> variables (both categorical and continuous and at both scales) in a
>> GLM-type analysis that, critically, allows for the lack of independence
>> between observations within the same site, caused by the nested sample
>> design?
>>
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