Re: st: How to obtain Rao-Scott chi(2) (not the F-stat) for two-way svy:tab

[Bo MacInnis <bo@macinnis.org>]

Thank you very much, Steve. However, for the same 2x2 table adjusting 
for the sampling weight, SAS produces (done by my colleague) Rao-Scott 
chi2(1) = 1.34 with p = .25, but I got F-stat = 1.48 with p = .22. Our 
boss is not comfortable considering these two statistics identical 
because their values are not close enough. I was wondering if SAS might 
do the Rao-Scott correction differently from Stata. Thank you much for 
your help! Bo

On 12/23/2010 7:31 AM, Steven Samuels wrote:
> Bo MacInnis-
>
> • Rao-Scott corrected chi square = (R-1)(C-1) x (corrected F)  where 
> R= no. of Rows  C = no. of Columns (Stata 11 Manual, page 130)
> • In your example with R=2, C=2, the statistics are identical.
> • SAS reports only the F approximation p-value, just as Stata does.
>
> Steve
>
> Steven J. Samuels
> sjsamuels@gmail.com
> 18 Cantine's Island
> Saugerties NY 12477
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>
>
> On Dec 22, 2010, at 1:36 PM, Bo MacInnis wrote:
>
> Dear Statlist mates,
>
> I'd like to obtain the Rao-Scott chi(2) statistic for two-way svy:tab. 
> The two-way svy:tab provides the Pearson statistics (uncorrected for 
> design-effect as well a design effect adjusted based on Rao-Scott 
> (1984). However, the design-based Pearson is converted into a F-stat. 
> In my project, I'd need the chi(2) version of the Rao-Scott statistic 
> (like what is provided in SAS, but I do not use SAS).
>
> Here is the output from a two-way (2x2) svy:tab:
>  Pearson:
>    Uncorrected   chi2(1)         =    2.3737
>    Design-based  F(1, 2803)      =    1.4764     P = 0.2244
>
> Thank you very much for your help!
> Bo
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