[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

From |
Richard Williams <Richard.A.Williams.5@ND.edu> |

To |
statalist@hsphsun2.harvard.edu, statalist@hsphsun2.harvard.edu |

Subject |
Re: st: KcKelvey & Zavoina's R2 in -fitstat- after -gologit2- |

Date |
Wed, 05 Mar 2008 09:05:25 -0500 |

At 05:42 AM 3/5/2008, Sara Mottram wrote:

Dear Statalist,First off, I don't think any of the pseudo R^2 measures is clearly superior to the others. Borrowing heavily from Long & Freese, I discuss them at

I have fitted a partial proportional odds model in Stata 9.2 using -gologit2-. In their book, Regression Models for Categorical Dependent Data using Stata, Long and Freese suggest that McKelvey & Zavoina's R2 most closely approximates the R2 from linear regression models (which I assume makes this the most suitable R2 to use). Following the advice on Richard William's website to use the v1 option, I have been able to use -fitstat- with -gologit2-, however, it does not produce the M&Z R2.

Please could someone tell me if this is because it does not make sense with a partial proportional odds model, in which case, is there a more appropriate measure of fit that I can use? Or do I need to specifically ask for M&Z R2 via an option?

http://www.nd.edu/~rwilliam/xsoc73994/L04.pdf

Second, you also don't get M&Z R2 after using mlogit. The formula for the statistic involves V(Y*), where Y* is the underlying latent variable that gives rise to the observed variable. But, with mlogit, there is no such underlying latent variable; and with gologit, it is not clear that there is such an underlying latent variable either (or if there is, I don't know how you would compute its variance). So, if you must use a Pseudo R^2, use one of the others. McFadden's R^2, which is the one generally reported by Stata, seems as good to me as any. (Although, from an aesthetic standpoint, I kind of like Cox Snell R^2. As pointed out in my notes, it isn't just a logical analog to OLS R^2; it is actually the same formula, albeit expressed in a way that nobody ever uses! But whether that makes it the best formula is another matter.)

-------------------------------------------

Richard Williams, Notre Dame Dept of Sociology

OFFICE: (574)631-6668, (574)631-6463

HOME: (574)289-5227

EMAIL: Richard.A.Williams.5@ND.Edu

WWW: http://www.nd.edu/~rwilliam

*

* For searches and help try:

* http://www.stata.com/support/faqs/res/findit.html

* http://www.stata.com/support/statalist/faq

* http://www.ats.ucla.edu/stat/stata/

**References**:**st: KcKelvey & Zavoina's R2 in -fitstat- after -gologit2-***From:*Sara Mottram <s.mottram@cphc.keele.ac.uk>

- Prev by Date:
**st: K median clustering** - Next by Date:
**st: SURE for CRM** - Previous by thread:
**st: KcKelvey & Zavoina's R2 in -fitstat- after -gologit2-** - Next by thread:
**st: RE: KcKelvey & Zavoina's R2 in -fitstat- after -gologit2-** - Index(es):

© Copyright 1996–2014 StataCorp LP | Terms of use | Privacy | Contact us | What's new | Site index |