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Re: st: Taking averages, etc.
For averages (-summarize-) and just about any similar measure or analytical
procedure, Stata ignores the missing values -- as if the observations in
question were not present. This happens automatically.
(This is different from an expression such as (a + b + c) / 3 , where a
single missing value spoils the result.)
Note that for commands that take several variables together, they generally
work on the set of observations having no missing values on all the
variables under consideration. So, as you adjust the set of variables, the
set of observations may shift -- depending on which variables have missing
values on what observations.
I hope this helps.
At 05:25 PM 12/16/2003 -0500, Adrian de la Garza wrote:
Can anyone tell me if it's possible to tell Stata to ignore missing
observations when computing averages, etc.? I think that if there is a
missing value in the observations considered, the average computed would
be then missing too... and I need it to intelligently choose how many
observations to use depending on whether observations are available,
Institute for Policy Studies
Johns Hopkins University
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