  # Re: RE: st: calculrating confidence Intervals in svypropstatements

 From 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
>
> 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/
```