Bookmark and Share

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: Warning on mlogit


From   Maria Sokolova <[email protected]>
To   [email protected]
Subject   st: Warning on mlogit
Date   Wed, 10 Jul 2013 18:43:04 +0200

Dear all,

Please give some advice on the following. All regression worked for
the full sample of several years. When I restrict the sample for 3
years only, the "Warning:  variance matrix is nonsymmetric or highly
singular" appears. I read the thread that was here several years ago
(http://www.stata.com/statalist/archive/2008-01/msg00980.html), but do
not really understand how it is applicable for me....
Mlogit has three choices and the clusters are for year-product (also
tried month-product, same thing). Choices are about 30% 55% 15% for a
given year.
the point is, that even the mlogit on the constant shows this warning...

the simplest (shortest) example is
mlogit pt dtime*, b(2) robust cluster(cluster1)

pt - three choices unordered
dtime - monthly dummies..

What can I do about this Warning?

Thanks again for your help,
Best,
Maria

--
- - - - -
Maria Sokolova
PhD student International Economics
The Graduate Institute of International and Development Studies
[email protected]
*
*   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/


© Copyright 1996–2018 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   Site index