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

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: using estimates coefficients |

Date |
Thu, 22 Mar 2012 08:52:39 +0000 |

You note that to use the mean age it is sufficient to -generate- a variable containing the mean age. True, but that is certainly not necessary. Consider this code (assuming _b[age] is available): su age, meanonly gen meanage = r(mean) gen x = _b[age] * meanage But you can do this instead su age, meanonly gen x = _b[age] * r(mean) What I also see (a lot) is something like egen meanage = mean(meanage) This probably looks natural enough, but it is very inefficient. But you could go further: as _b[age] * r(mean) is yet another constant, it can be manipulated as such; there is no need to put it in a variable. I've not got a good grasp on your overall problem but it seems that it may reduce to looping over models and just keeping track of _b[age] from -regress- and r(mean) from -summarize- without needing to calculate that many variabes at all. Nick On Thu, Mar 22, 2012 at 8:41 AM, Chiara Mussida <cmussida@gmail.com> wrote: > The proper way of dealing with sum and products of coefficients across > different model saved by "estimate save" it is to compute the sum > and/or product in each model separately, as for example: > > ge x= _b[age]* meanage, where mean age is the mean value of age in my dataset. > > this will be done for each of the 7 model. At the end I will sum the > variables obtained across each model stored. I hope I will be able to > save the variables of interest into the same file. > > Chiara > > > > On 21/03/2012, Muhammad Anees <anees@aneconomist.com> wrote: >> Althoug I am not sure, I have tried this and it has worked; >> >> regress dv1=in1 in2 in3 in4 >> display _b[in1] >> gen agea=-.00036117 >> regress dv1=in1 in2 in3 in4 >> display _b[in1] >> gen ageb=-.00036117 >> gen sumab=agea+ageb >> display sumab >> >> and so on to include other coefficients from other models. >> >> I Hope this may be of help >> >> Anees >> >> On Wed, Mar 21, 2012 at 9:24 PM, Chiara Mussida <cmussida@gmail.com> wrote: >>> Dear All, >>> I run (7) different equations, simple reg command. I now have to play >>> with the coefficient estimates of each equation, _b[name] >>> >>> Each of the 7 estimates have been carried out and stored with diffrent >>> names (model1,..., model7). I now must sum the coefficients of each >>> regressors of the different models, like the sum of _b[age] for all >>> the 7 models. >>> >>> How should I compute (manually) this sum across all the models? >>> _b[age] model1 + _b[age] model2 + ... + _b[age] model7 >>> >>> I will have also to include the mean values of each characteristics, >>> but for this it is enough to gen an ad hoc variable for each case. * * 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/

**References**:**st: using estimates coefficients***From:*Chiara Mussida <cmussida@gmail.com>

**Re: st: using estimates coefficients***From:*Muhammad Anees <anees@aneconomist.com>

**Re: st: using estimates coefficients***From:*Chiara Mussida <cmussida@gmail.com>

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