This could be condensed to three lines not four, with perhaps some gain
in clarity.
egen Sum = total(Response), by(Strata)
egen Count = count(Response), by(Strata)
gen MeanOthers = (Sum - Response) / (Count - 1)
In addition there is an -egen- function -sumoth()- in -egenmore- on SSC.
Nick
[email protected]
Nick Cox
You refer to the count option.
There is a -count- command and a -count()- function for -egen-.
I guess you mean the -count- command. As you say, it is not suitable for
this purpose. But the -count()- function for -egen- is.
In your example, the variable name -SumOthers- might confuse. I'll
rename it:
Obs Strata Response MeanOthers
1 1 3 2
2 1 1
3 1 2
4 2 1
5 2 3
6 1 3
You want
egen Sum = total(Response), by(Strata)
replace Sum = Sum - Response
egen Count = count(Response), by(Strata)
gen MeanOthers = Sum / (Count - 1)
Another way to do it, which is explained in the FAQ cited, is
egen Count = total(Response < .), by(Strata)
For future publications note the tricky singular and plural, from Latin:
one stratum, two or more strata.
Nick
[email protected]
Chao Yawo
Thanks for the suggestions. I was able to create (Sum of Others - This
Value), as suggested, hence I have the numerator for creating the Mean
of Others. However, I am running into a bit of a problem creating the
denominator.
Here is what my data looks like at the moment:
Obs Strata SumOthers MeanOthers
1 1 3 2
2 1 1
3 1 2
4 2 1
5 2 3
6 1 3
The Mean for observation 1 = ([3+1+2+3]-3 / 4 - 1) = 2.
That is, to the get the mean of others, I have to divide the "Sum of
Others - This Value" by a denominator that counts the "number of
observations within each strata - 1". I looked at the Count option,
however, I realized that it saves it output as a scalar, hence I am
unable to get the denominator required.
> > From: Nick Cox <[email protected]>
> > This is a FAQ. See
> >
> > FAQ . . Creating variables recording prop. of the
> other
> > members of a
> > group
> > 4/05 How do I create variables summarizing
> for
> > each
> > individual properties of the other
> members
> > of a
> > group?
> >
> > http://www.stata.com/support/faqs/data/members.html
> >
> > The key principle for sums is elementary
> >
> > Sum of others = Sum of all - This value
> >
> > And for means correspondingly
> >
> > Mean of others = (Sum of all - This value) / (Number
> in
> > group - 1)
> >
> > Other summary measures are more challenging, but the
> FAQ
> > gives advice.
> >
> > The only obvious complication is that you want to sum
> > across variables
> > before you summarize across the other members of this
> > group. That will
> > often be easiest through -egen, rowtotal()-.
Chao Yawo
> > I am examining the effect of stigmatizing attitudes of
> > specific health
> > behaviors, using a demographic health survey (DHS).
> DHS
> > respondents were
> > required to indicate (by a YES, NO, DONT KNOW)
> whether:
> >
> > (1) whether they would buy a vegetable from a vendor
> who
> > has HIV, (2)
> > whether they would keep their family member's HIV
> > infection a secret
> > (3) whether they would be willing to care for a
> relative
> > who is infected
> > with HIV
> > (4) wheether a female teacher infected with HIV should
> be
> > allowed to
> > continue teaching in school
> >
> > I want to calculate a summary score that reflects
> community
> > attitude
> > (the attitudes of all members of the community on
> these
> > variables ---
> > that is the score must EXCLUDE those of the
> respondent, and
> > INCLUDE
> > those of all others. In some literature, this is
> referred
> > to as
> > non-self mean.
> >
> > Since in the DHS, clusters (V022) are the lowest level
> from
> > which a
> > sample of households is drawn (i.e. these are
> typically the
> > primary
> > sampling unit), I want a score based on the responses
> of
> > all people in
> > the same strata (PSU) as the respondent, but excluding
> the
> > respondent's
> > responses. For example, to compute this score for an
> > individual A who
> > resides in PSU B, we sum the stigma scores (over all
> the 4
> > variables) of
> > all individuals in PSU B, with the exceptoin of
> respondent
> > A.
> >
> > I would be very grateful if you could give me some
> pointers
> > about how to
> > create this summary score (over all the 4 variables).
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