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From | Aniruddha Rajan <aniruddha.rajan@googlemail.com> |
To | <statalist@hsphsun2.harvard.edu> |
Subject | Re: st: Statistically significant difference in R Squared |
Date | Thu, 23 Aug 2012 19:24:37 +0100 |
Thanks for your response Anees. In this case I don't think it is possible to look at information criteria or other forms of model comparison as the empirical representation of the underlying model does not change - it is fixed by theory. Hence the change I am attempting to find a way to examine is the model fit in this period versus last period. Regards, Ani On 23/08/2012 19:06, "Muhammad Anees" <anees@aneconomist.com> wrote: >If you have to compare the two models, why not read on on the >comparison of nested and non-nested models on the list (by searching >the archives) and selecting the best or preferred model using the AIC, >BIC or HQIC. > >Comparisons based on R-squared ( or adjusted R-squared) does not need >be tested _Statistically. Simply you can chose a model with higher >R-squared ( or adjusted R-squared). Otherwise Nick's suggestion is >what seems to be the most appropriate one to me. > >Best >Anees > >On Thu, Aug 23, 2012 at 11:07 PM, Aniruddha Rajan ><aniruddha.rajan@googlemail.com> wrote: >> Thanks very much for your helpful response Nick. The gist of what I'm >> trying to do is to see whether the data I have conforms to a specified >> theoretical model to a greater extent during the second period as >>compared >> to the first. I guess the residual plot should be good enough. Do any >> formal tests for something like this exist? >> >> On 23/08/2012 17:56, "Nick Cox" <njcoxstata@gmail.com> wrote: >> >>>I don't think the question makes much sense inferentially for several >>>quite different reasons. But looking at the residuals as a function of >>>time and seeing whether they vary systematically could be a very >>>sensible and helpful check. >>> >>>Nick >>> >>>On Thu, Aug 23, 2012 at 5:09 PM, Aniruddha Rajan >>><aniruddha.rajan@googlemail.com> wrote: >>> >>>> I am running a time-series regression model over a 10 year period. I >>>>would >>>> be interested in splitting the sample into two five year periods and >>>>finding >>>> out whether the model has a statistically significantly higher R^2 >>>>during >>>> the second period as compared to the first. Is there a test for this, >>>>and if >>>> so is it possible to implement in 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/ >> >> >> * >> * 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/ > > > >-- > >Best >--------------------------- >Muhammad Anees >Assistant Professor/Programme Coordinator >COMSATS Institute of Information Technology >Attock 43600, Pakistan >http://www.aneconomist.com >* >* 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/