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Re: RE: st: calculrating confidence Intervals in svypropstatements


From   <hk489@nyu.edu>
To   statalist@hsphsun2.harvard.edu
Subject   Re: RE: st: calculrating confidence Intervals in svypropstatements
Date   Thu, 02 Sep 2004 20:35:29 -0400

Dear Austin and other lister,

I used the code from jpitblado@stata.com, which you let me know in your e-mail the other day. I believe I didn't make any typographical error, but STATA didn't calculate CIs and ended up with a caution message  ( invalid name  r(199);. 

Below is the outputs: 


**** START

    2. svyprop cat1Rr cat2Rr cat3Rr
 
    Survey proportions estimation

  +---------------------------------------------------------+
  | cat1Rr   cat2Rr   cat3Rr   Obs   Est. Prop.   Std. Err. |
  |---------------------------------------------------------|
  |      0        0        0    65     0.202852    0.026513 |
  |      0        0        1    29     0.078938    0.020018 |
  |      0        1        0    13     0.028383    0.009759 |
  |      0        1        1     2     0.003007    0.002141 |
  |      1        0        0     5     0.005753    0.003897 |
  |---------------------------------------------------------|
  |      1        0        1     1     0.003676    0.003676 |
  |      1        1        0     2     0.002165    0.001566 |
  |      1        1        1     1     0.002011    0.002014 |
  |      2        2        2   246     0.673215    0.031302 |
  +---------------------------------------------------------+



     3 . di "cat1Rr  cat2Rr  cat3Rr     (Lower Bound, Upper Bound)"
      cat1Rr  cat2Rr  cat3Rr     (Lower Bound, Upper Bound)
      
     4 . forvalues i=0/2 {
        2. forvalues j=0/2 {
        3. forvalues k=0/2 {
        4. qui gen i`i'j`j'k`k'=(cat1Rr==`i' & cat2Rr==`j' & cat3Rr==`k') 
        5.    qui su i`i'j`j'k`k'
        6.  if r(max)>0 & r(N)>0 {
        7.  qui svylogit i`i'j`j'k`k'
        8.  scalar lcb = invlogit(_b[_cons]-invttail(e(df_r),.025)*_se [_cons])
        9. scalar ucb = invlogit(_b[_cons]+invttail(e(df_r),.025)*_se[_cons])
       10.  di "   `i'       `j'       `k'       ( " scalar(lcb) " , "
       11. scalar(ucb) " )"
       12. }
       13. }
       14. }
       15. }
         0       0       0       ( .00203944 , 
      ( invalid name
      r(199);
*** END


Did I make any mistake? Any suggestion?  Many thanks for your invaluable help to a novice STATA user.   Hong 









----- Original Message -----
From: "Nichols, Austin" <ANichols@ui.urban.org>
Date: Wednesday, September 1, 2004 6:16 pm
Subject: RE: st: calculrating confidence Intervals in svyprop statements

> Note that you report nine categories, and I don't think your CIs 
> will be
> plausible, given the number of obs and apparent weighting and 
> survey design.
> Plus your categories are suspect, since if they were 0/2 you would 
> have 27
> categories instead of nine. But mine is not to reason why. Using 
> code from
> jpitblado@stata.com,
> 
> di "cat1Rr  cat2Rr  cat3Rr     (Lower Bound, Upper Bound)"
> forvalues i=0/2 {
> forvalues j=0/2 {
>  forvalues k=0/2 { 
>    qui gen i`i'j`j'k`k'=(cat1Rr==`i' & cat2Rr==`j' & cat3Rr==`k') 
>    qui su i`i'j`j'k`k'
>    if r(max)>0 & r(N)>0 {
>        qui svylogit i`i'j`j'k`k'
>        scalar lcb = invlogit(_b[_cons]-
> invttail(e(df_r),.025)*_se[_cons])        scalar ucb = 
> invlogit(_b[_cons]+invttail(e(df_r),.025)*_se[_cons])        di "  
> `i'       `j'       `k'       ( " scalar(lcb) " , "
> scalar(ucb) " )"
>    }
>  }
> }
> }
> 
> gives CIs that are constructed independently and cannot be used to
> eyeball-test joint hypotheses about proportions. Caveat emptor.
> 
> -----Original Message-----
> From: hk489@nyu.edu [hk489@nyu.edu]
> Sent: Wednesday, September 01, 2004 5:35 PM
> To: statalist@hsphsun2.harvard.edu
> Subject: Re: st: calculrating confidence Intervals in svyprop 
> statements
> Despite of some valuable comments of you, I couldn't solve the 
> problem. At
> the last reply, Jeff explained about how to get CI with "SVYMEAN"
> statements. I need to calculate CIs with "SVYPROP" statements, 
> however.Below is the table explaining how I calculate 8 Est. Prop. 
> 
> *
> *   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/
> 

*
*   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/



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