Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.

# Re: st: loop

 From Nick Cox To statalist@hsphsun2.harvard.edu Subject Re: st: loop Date Thu, 29 Mar 2012 15:59:25 +0100

```Commenting only on

> reg lwage \$x if fem==0
> predict pip if fem==0, xb
> forvalues k = 1 2 to 7 {
>        predict pip`k' if fem==0 & occ`k'==1, xb
> }

Note that these are exactly the same predictions. You are just
selecting different subsets of observations. So
no obvious purpose is served by -predict-ing the same variable over
and over again.

Nick

On Thu, Mar 29, 2012 at 3:32 PM, Chiara Mussida <cmussida@gmail.com> wrote:
> Dear All,
> I wrote a loop for wage regressions to obtain the predicted wages if
> men are paid as men at each occupation:
>
> reg lwage \$x if fem==0
> predict pip if fem==0, xb
> forvalues k = 1 2 to 7 {
>        predict pip`k' if fem==0 & occ`k'==1, xb
> }
> summarize pip, meanonly
> scalar xMbM=r(mean) /*Predicted wages if men are paid as men*/
> forvalues k = 1 2 to 7 {
>        summarize pip`k', meanonly
>        scalar xMbM`k'=r(mean) /*Predicted wages if men are paid as men at
> each occupation*/
> }
>
> I now want to get the xMbM (and also xFbF for females) by occupation.
> For each occupation I want the product between ythe mean individual
> charachteristics (xM) and the coefficients (bM). I tried with this
> loop, but i'm not sure it's the correct one:
>
> reg lwage \$x if fem==0
> predict pip if occupation==1, xb
> forvalues k = 1  {
>        predict pip`k' if fem==0 & occ`k'==1, xb
> }
> summarize pip, meanonly
> scalar xMbM=r(mean) /*Predicted wages if men are paid as men*/
> forvalues k = 1 {
>        summarize pip`k', meanonly
>        scalar xMbM`k'=r(mean) /*Predicted wages if men are paid as men at
> each occupation*/
> }
>
> More precisely, i'm not sure this wille give me each product between
> mean values of characteristics (x, for M or F) and estomated wage
> equation coefficients (b, for M or F) at each 1...7 occupation.
>

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/
```

• References:
• st: loop
• From: Chiara Mussida <cmussida@gmail.com>