st: differences of mean

[Chiara Mussida <cmussida@gmail.com>]

Dear All,
I have to calculate the difference of mean log wages of men and women.
My dataset contains the variable lwage which is the log of wages. I
tried to generate the mean wage (also by occupation, for a more
detailed difference):

bys occupation: egen wage=mean(lwage)
ge wage1f=wage if occupation==1 & fem==1
ge wage1m=wage if occupation==1 & fem==0
ge diff1=wage1m - wage1f if occupation==1

but this gave me a variable diff1 with no observations, since the mean
lwage for men is missing when the mean lwage for men it is not, and
viceversa. Again, if I do replace the missing values of men and women
with 0 this gives me false results (I know there is a difference
between missing and 0).

How should I get my variable diff= mean(lwage men) - mean(lwage
women)? Total difference and/or difference by occupation.

Thanks a lot

Chiara
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