# Re: st: svyregress

 From anju parthan <[email protected]> To [email protected] Subject Re: st: svyregress Date Mon, 24 Jan 2005 15:50:55 -0800 (PST)

```Hi Clive

Thanks for your input. I still have a question. Does
the command collin incorporate strata, psu and
pweight?

I ran the svyreg and collin as you suggested.   But
when I ran svyreg for each of the independent
variables to calculate the VIF manually, the VIF
values are slightly different than the output from
collin.
So it looks like collin does not take into account
strata, psu, and pweights. Am I right?

Anju
--- Clive Nicholas <[email protected]>
wrote:

> Anju Parthan wrote:
>
> > I have complex survey data. I am trying to run vif
> > after svyregress, but I get this error message
> >
> > . vif
> > r(301);
> >
> > How can I calculate vif with svyregress?
>
> SSC. An example, taken
> from one of my own 'cloned' datasets:
>
> . use ees99, clear
>
> . svyset [pweight=weight]
> pweight is weight
>
> . svyreg probvcon sex age educ turecode
>
> Survey linear regression
>
> pweight:  weight
> Number of obs    =       920
> Strata:   <one>
> Number of strata =         1
> PSU:      <observations>
> Number of PSUs   =       920
>
> Population size  =   924.698
>                                                 F(
> 4,    916)  =      5.76
>                                                 Prob
> > F         =    0.0001
>
> R-squared        =    0.0346
>
----------------------------------------------------------------------------
>   probvcon |      Coef.   Std. Err.      t    P>|t|
>    [95% Conf. Interval]
>
-----------+----------------------------------------------------------------
>        sex |   .0952869   .2302624     0.41   0.679
>   -.3566143    .5471881
>        age |  -.0283479   .0078918    -3.59   0.000
>   -.0438359   -.0128599
>       educ |   .0153538   .0173196     0.89   0.376
>   -.0186367    .0493443
>   turecode |  -.4211906   .1369806    -3.07   0.002
>   -.6900217   -.1523596
>      _cons |   59.86004   15.52017     3.86   0.000
>    29.40094    90.31913
>
----------------------------------------------------------------------------
>
> . collin probvcon sex age educ turecode
>
>   Collinearity Diagnostics
>                       SQRT
> Cond     Cond          R-
>   Variable     VIF    VIF  Tolerance    Eigenval
> Index1   Index2   Squared
>
----------------------------------------------------------------------------
>   probvcon     1.03   1.01 0.9749   1.1722     1
> 1.0000   1.0000    0.0251
>   sex          1.01   1.01 0.9885   1.1475     2
> 1.0107   2.4812    0.0115
>   age          1.03   1.01 0.9741   0.9868     3
> 1.0899   3.2101    0.0259
>   educ         1.02   1.01 0.9791   0.8671     4
> 1.1627   4.1625    0.0209
>   turecode     1.02   1.01 0.9843   0.8264     5
> 1.191    8.3130    0.0157
>                                                6
>      391.5044
>
----------------------------------------------------------------------------
>   Mean VIF     1.02                    Condition
> Number     1.1910  391.5044
>                        Determinant of correlation
> matrix    0.9511
>                        Cond Index1 from deviation
> SSCP (no intercept)
>                        Cond Index2 from scaled raw
> SSCP (w/ intercept)
>
> CLIVE NICHOLAS        |t: 0(044)7903 397793
> Politics              |e: [email protected]
> Newcastle University  |http://www.ncl.ac.uk/geps
>
> *
> *   For searches and help try:
> *
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> *   http://www.stata.com/support/statalist/faq
> *   http://www.ats.ucla.edu/stat/stata/
>

=====
____________________________________________________________

Anju Parthan,
Doctoral Candidate,
The University of Texas at Austin, PHAR-PHARMACY ADMIN
1 UNIVERSITY STATION A 1930, AUSTIN, TX-78712
Tel: (512) 459-4942; Fax: (512) 471-8762

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```