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| From | Andrea Mannberg <andrea.mannberg@econ.umu.se> |
| To | "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu> |
| Subject | SV: st: Reoprob - problem with convergence and superxt |
| Date | Sun, 19 Jun 2011 21:19:12 +0200 |
Thanks Maarten, Actually, I did go back to the data to try to figure out what was wrong with the variable. The strange thing is that the number of observations in each category is fairly well balanced. It is only one category in one time period that has a substantially higher number of observations than the others. I must be missing something, so I'll go back to the data again to try to figure out what it is. Thanks a lot for taking time to answer my question! Cheers Andrea ________________________________________ Från: owner-statalist@hsphsun2.harvard.edu [owner-statalist@hsphsun2.harvard.edu] för Maarten Buis [maartenlbuis@gmail.com] Skickat: den 17 juni 2011 17:48 Till: statalist@hsphsun2.harvard.edu Ämne: Re: st: Reoprob - problem with convergence and superxt On Fri, Jun 17, 2011 at 4:13 PM, Andrea Mannberg wrote: > I am trying to estimate a random effects ordered probit model of the form > > reoprob trust_trade ptreatment treatment year99 tradeout age sex read write maleadult femaleadult oxen livestock landarea security1 security2 conflict zone , i(hhid) quadrat(12) level(95) > > Where the dependent variable has 4 categories. I have tried changing the quadrature, the level, and the tolerance levels (ltol and tol) , nothing helps. Stata is having a problem of getting the "constant only" model to converge. The constant only model is a very simple model. So, if that does not converge than that is an indication that there is something seriously wrong with your model, and it is unlikely that tricks like -superxt- are going to work in such situations. In those situations you need to go back to your data and inspect that very carefully and find the problem. In this case I suspect that your dependent variable has some very rare categories, which means you'll probably need to merge that category with an adjacent category. 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/ * * 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/