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From |
Nick Cox <njcoxstata@gmail.com> |

To |
"statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu> |

Subject |
Re: st: non-linear models not converging |

Date |
Wed, 22 May 2013 14:13:14 +0100 |

This is my missing #7. Nick njcoxstata@gmail.com On 22 May 2013 14:08, Maarten Buis <maartenlbuis@gmail.com> wrote: > One trick that often helps with this kind of model is to make sure > that all independent/explanatory/right-hand-side/x-variables have the > value 0 at a meaningful point within (or near) the range of the data. > So don't use "year of birth in years since the year 0" but for example > "year of birth in decades since 1950" ( = (year of birth - 1950 ) / 10 > ). The logic is that these models add a model for the constant. If > that refers to a point way outside the range of the data, it sometimes > becomes difficult. > > On Wed, May 22, 2013 at 2:56 PM, James Bernard <jamesstatalist@gmail.com> wrote: >> Thanks both, >> >> I am running -xtpoisson random effect.... it does not converge! >> >> Thanks, >> James >> >> >> On Wed, May 22, 2013 at 8:53 PM, Kelvin Mulungu >> <kelvin.statalist@gmail.com> wrote: >>> Bernard, >>> >>> I had the same problem sometime last week. Am not sure this is a >>> standard solution but it worked for me. Start simple- begin with >>> simple models in the line of your problem and build on to the >>> complicated model you want run and see where exactly the model will >>> stop converging. Add variables in a step-wise fashion, i.e. start with >>> what you think are the most crucial variables and lets say begin with >>> two and keep adding the variables you think influence your Y. >>> >>> Finally, check your data to make sure it can handle that type of >>> model. In some cases, the data may not allow you to run such a model. >>> >>> Hope this helps, though am not sure what type of non-linear model you >>> are trying to run. >>> >>> On Wed, May 22, 2013 at 3:43 PM, James Bernard <jamesstatalist@gmail.com> wrote: >>>> Hi all, >>>> >>>> I understand that the numeric methods used for estimation of models in >>>> Stata (and any other package) may result in a model that does not >>>> converge. >>>> >>>> Do you happen to know of any trick to help make the model converge? To >>>> increase the chance of converging? >>>> >>>> Thanks, >>>> James >>>> * >>>> * 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/ >>> * >>> * 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/ >> * >> * 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/ > > > > -- > --------------------------------- > Maarten L. Buis > WZB > Reichpietschufer 50 > 10785 Berlin > Germany > > http://www.maartenbuis.nl > --------------------------------- > * > * 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/ * * 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/

**References**:**st: non-linear models not converging***From:*James Bernard <jamesstatalist@gmail.com>

**Re: st: non-linear models not converging***From:*Kelvin Mulungu <kelvin.statalist@gmail.com>

**Re: st: non-linear models not converging***From:*James Bernard <jamesstatalist@gmail.com>

**Re: st: non-linear models not converging***From:*Maarten Buis <maartenlbuis@gmail.com>

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