Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
st: gamma family - alpha and theta parameters - xtgee
From
"Guillermo A. Sandoval (UofT)" <[email protected]>
To
"[email protected]" <[email protected]>
Subject
st: gamma family - alpha and theta parameters - xtgee
Date
Tue, 28 May 2013 23:36:31 +0000
Dear
I am using xtgee with gamma distribution. I understand that for gamma distribution, one needs to define the parameters alpha and theta, which define the shape of the distribution function. Please see http://en.wikipedia.org/wiki/Gamma_distribution. My variable is continuous (mortality rates in hospitals) and distributes pretty much like the one in wekipedia that says k=1 and theta=2.
In xtgee, it looks like one cannot define these parameters. I guess my question is, is this necessary (if yes, how)? or xtgee actually estimates them and I don't really need to worry about that?
Thanks in advance
Guillermo
----
Guillermo A. Sandoval
PhD Candidate in Health Services Research
Institute of Health Policy, Management and Evaluation
University of Toronto
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/faqs/resources/statalist-faq/
* http://www.ats.ucla.edu/stat/stata/