Notice: On March 31, it was **announced** that Statalist is moving from an email list to a **forum**. The old list will shut down on April 23, and its replacement, **statalist.org** is already up and running.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

From |
William Hauser <whauseriii@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: What is the effect of centering on marginal effects? |

Date |
Fri, 3 Aug 2012 08:13:16 -0400 |

Dear all, I'm fairly confident that mean centering does nothing to resolve collinearity. I believe it does fool some of the diagnostic tools though and that's probably why the belief that it somehow solves the problem persists. Mean centering simply shifts the collinearity onto the intercept term. Mean centering adds no new information to the model and that's the problem - the data lack the necessary information for the model to partial out the effects in a precise and stable manner. Perhaps this is effect is different for interaction terms, but I fail to see how that's the case. Collinearity means the independent effects of the collinear variables cannot be precisely estimated. The point of interaction terms is that they be analyzed jointly anyway. The use of the margins and marginsplot commands accomplish this with such ease (and polish) that I would heartily recommend their use. Will * * 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: What is the effect of centering on marginal effects?***From:*David Hoaglin <dchoaglin@gmail.com>

**Re: st: What is the effect of centering on marginal effects?***From:*Nick Winter <njgwinter@gmail.com>

- Prev by Date:
**Re: st: comparing coefficients across models** - Next by Date:
**Re: Re: st: Comparing coefficients across sub-samples** - Previous by thread:
**Re: st: What is the effect of centering on marginal effects?** - Next by thread:
**Re: st: What is the effect of centering on marginal effects?** - Index(es):