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From |
Maarten Buis <maartenlbuis@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Fwd: Comparing marginal effects of two subsamples |

Date |
Mon, 24 Oct 2011 18:18:11 +0200 |

On Mon, Oct 24, 2011 at 5:49 PM, Jianhong Chen wrote: > Thank you very much. Just to confirm, there is no need to compare > marginal effect by splitting sample. As long as I provide the > incidence-rate ratio for interaction term and it is sigificant, I can > say that the hypothesized interaction is supported. Right? I cannot confirm that statement, in the sense that I will not give a "recipe" for how to get to a conclusion(*). The point of both incidence rate ratios and marginal effects to get interpretable numbers. At the beginning of this thread I gave an example of how to do so <http://www.stata.com/statalist/archive/2011-10/msg00938.html>. So the first step is to interpret your coefficients. If you want to do testing, you need to figure out what the null hypothesis is that you want to test, i.e. you need to translate a statement like "the interaction term is significant" to either incidence rate ratios or marginal effects. After that, performing the test is trivially easy. -- Maarten (*) I know I am being mean by not giving you an easy answer (which exists), but when dealing with interactions there are just so many things that can go horribly wrong that following some "recipe" will only lead to more errors. The only option to do such things right is to really understand the numbers you are producing. It is not hard (I gave you an example), and that bit of effort will really pay off. -------------------------- 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/

**References**:**st: Fwd: Comparing marginal effects of two subsamples***From:*Jianhong Chen <jianhongchen1985@gmail.com>

**Re: st: Fwd: Comparing marginal effects of two subsamples***From:*Maarten Buis <maartenlbuis@gmail.com>

**Re: st: Fwd: Comparing marginal effects of two subsamples***From:*Jianhong Chen <jianhongchen1985@gmail.com>

**Re: st: Fwd: Comparing marginal effects of two subsamples***From:*Maarten Buis <maartenlbuis@gmail.com>

**Re: st: Fwd: Comparing marginal effects of two subsamples***From:*Jianhong Chen <jianhongchen1985@gmail.com>

**Re: st: Fwd: Comparing marginal effects of two subsamples***From:*Maarten Buis <maartenlbuis@gmail.com>

**Re: st: Fwd: Comparing marginal effects of two subsamples***From:*Jianhong Chen <jianhongchen1985@gmail.com>

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