Re: st: loop

[Nick Cox <njcoxstata@gmail.com>]

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.
>

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