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From |
John Francis <francisj71@googlemail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Obtaining rrr's of margins after mlogit |

Date |
Thu, 22 Mar 2012 12:03:30 +0100 |

Let's see if I can clear this up a little, I use -mlogit- with the -rrr- option, which gives me as an output: .[cat1] . .edu .1 [...] .2 [...] . .edu#coh .1 1 [...] .2 1 [...] Now, what do I do in order to check how much the effect has changed between cohorts, and whether or not said change is significant? How does the constant play into this? I think these things would be fairly obvious to see if I could use -margins, over()-, but as it is, the -mlogit- output is quite confusing to me... John On Thu, Mar 22, 2012 at 11:41 AM, Maarten Buis <maartenlbuis@gmail.com> wrote: > Maybe I am still not understanding your question, as the solution > appears to me to just not to use -margins- or -lincom- but directly > specify the -rrr- option in your -mlogit- command: > > mlogit depvar i.edu##i.coh i.sex##i.coh, b(2) rrr > > This will directly give you the ratio or relative risk ratios that you > seem to be looking for. > > Hope this helps, > Maarten > > On Thu, Mar 22, 2012 at 11:31 AM, John Francis > <francisj71@googlemail.com> wrote: >> Thank you Maarten, >> >> That part I had figured out already. Please let me respecify: what I >> want is to first run >> -mlogit-, say >> >> .mlogit depvar i.edu##i.coh i.sex##i.coh, b(2) nolog >> >> Then, I would first like to get the marginal effects for each outcome >> in order to get RRRs of the interaction terms, with each of the four >> categories in relation to category 2. The reason I want to do this is >> so that I can use the method described in your Stata-Tip regarding the >> interpretation of interaction effects in nonlinear models. This means >> that I >> would run >> >> .forval i = 1/4 { >> .margins, over(i.edu i.coh) expr(exp(xb(#`i'))) post >> .est sto m`i' >> .} >> >> so that afterwards, I could use -lincom- in order to interpret the >> interaction effects as RRRs. Same goes for the interaction of sex and >> coh. This is how far I got so far. Now of course, Stata tells me >> "Warning: prediction constant over observations." I take that to mean >> that the specification of xb() is wrong, yet I don't know how I should >> change it. >> >> Besides, is this the correct way to apply the procedure described by >> you to a multinomial logit model? >> >> Regards, >> John >> >> On Thu, Mar 22, 2012 at 9:14 AM, Maarten Buis <maartenlbuis@gmail.com> wrote: >>> On Wed, Mar 21, 2012 at 5:37 PM, John Francis wrote: >>>> I have a question on obtaining margins as relative risk ratios instead >>>> of probabilities after I run the mlogit command. >>> >>> You can specify the -rrr- option in -mlogit-. >>> >>> 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/ > > > > -- > -------------------------- > 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/

**Follow-Ups**:**Re: st: Obtaining rrr's of margins after mlogit***From:*Maarten Buis <maartenlbuis@gmail.com>

**References**:**st: Obtaining rrr's of margins after mlogit***From:*John Francis <francisj71@googlemail.com>

**Re: st: Obtaining rrr's of margins after mlogit***From:*Maarten Buis <maartenlbuis@gmail.com>

**Re: st: Obtaining rrr's of margins after mlogit***From:*John Francis <francisj71@googlemail.com>

**Re: st: Obtaining rrr's of margins after mlogit***From:*Maarten Buis <maartenlbuis@gmail.com>

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