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

[Sara Mottram <s.mottram@cphc.keele.ac.uk>]

Dear Statalist,

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?

There was a similar question posed last year, but the solution suggested 
to that post (see below) gives me an estimate of "." I'm not sure what 
that means.

sysuse auto
logit foreign price
fitstat
estadd scalar r2_mz = r(r2_mz)

and then tabulate using:

estout ., eform cells(n se(par)) stats(r2_mz) style(fixed)

or:

esttab ., eform se scalars(r2_mz)


Best wishes,
Sara

--
Sara Mottram	
Research Assistant: Biostatistics
Primary Care Musculoskeletal Research Centre
Primary Care Sciences
Keele University
Staffordshire, ST5 5BG
Tel:  	+44 (0) 1782 584711
Fax:  	+44 (0) 1782 583911
Email:	s.mottram@cphc.keele.ac.uk

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