Hello Guillermo,
This code might help. I only tested with the two cases you sent, it might
need some adjutment.
Here I am creating only one vble for the number of kids, but you can easily
rename
the variable to be father-mother specific and you will get two vbles after
you merge
everything.
If your dataset is too big you might want to read the data twice instead of
preserving/restoring.
/*Make datasets for fathers and mothers with their number
of kids*/
use hm.dta, clear /*your dataset*/
foreach var of varlist fatherm motherm {
preserve
qui keep if `var'!=.
sort hhid `var'
by hhid `var': gen sibl=_N /*here you can make the name father-mother
specific*/
by hhid `var': keep if _n==1
keep hhid `var' sibl
ren `var' member
sort hhid member
save `var'.dta, replace
restore
}
use hm.dta
sort hhid member
merge hhid member using fatherm
drop _merge
sort hhid member
merge hhid member using motherm, update
drop _merge
I didn�t put too much effort in writting it short, you might be able to
shorten it.
Hope this helps!
Marcela
--------------------------------------------
Universidad Alberto Hurtado
Erasmo Escala 1835
Santiago, Chile
Phono: 671-7130 anexo 267
----- Original Message -----
From: <[email protected]>
To: <[email protected]>
Sent: Wednesday, August 28, 2002 4:19 PM
Subject: st: Extensions to: Creating variables recording properties of the
other members of a group
> When working with twin household/individual datasets, this is one of the
most
> useful FAQs:
> http://www.stata.com/support/faqs/data/members.html
> However, there are a few issues I couldn't solve with the information
included
> there, or not efficiently at least. I would like to solve my problem and,
if
> worthwhile, write an extension of the FAQ. The problem refers to the fact
that
> sometimes you may need to record for one individual the properties not of
the
> whole group, but of another member of the group in particular.
> In my example, I have a household survey where I don't have direct
information
> about the number of kids of each individual, but I have something like
this:
> hhid and member are just the household id and number of member. Variables
> fatherm and motherm tell you the number of the member of the father and
the
> mother, if in the household:
> hhid member fatherm motherm
> 1 1 - -
> 1 2 - -
> 1 3 1 2
> 1 4 1 2
> 1 5 1 2
>
> 2 1 - -
> 2 2 - 1
> 2 3 - 2
> ...
> Family one is a couple with three kids. Family two is a grandma, the
daughter,
> and a grandchild.
> I want to create the variable ownkids that gives me the number of own kids
> living in the house:
> hhid member ownkids
> 1 1 3
> 1 2 3
> 1 3 0
> 1 4 0
> 1 5 0
>
> 2 1 1
> 2 2 1
> 2 3 0
>
> My force brute solution, which makes a lot of unnecessary comparisons and
takes
> very long (because I generate and drop many variables) is of the form:
with
> maxmem being the number of members of each household (group i, max is the
number
> of groups),
> forvalues i = 1/`max' {
> qui sum member if group==`i'
> local maxmem=r(max) forvalues j = 1/`maxmem' {
> di "-----------Household number `i', number of members: `maxmem'"
> forvalues k = 1/`maxmem' {
> di "Household `i', member `j', comparing with `k'"
> qui gen a=motherm==`j' if member==`k'&group==`i'
> qui egen b=max(a)
> qui replace mkids=mkids+b if member==`j'&group==`i'
> drop a b
> qui gen a=fatherm==`j' if member==`k'&group==`i'
> qui egen b=max(a)
> qui replace fkids=fkids+b if member==`j'&group==`i'
> drop a b
> }
> }
> }
>
> This creates two variables, mkids and fkids, which are the number of kids
for
> mothers and fathers. For each member of the household, I compare if . The
egen,
> replace, drop, takes very long, and even longer if the dataset in memory
is
> large (I had to partition the dataset in 25 parts to make this run
faster).
> The main problem (the main awkwardness in this program) is that I gen,
egen,
> etc. because I could not just create a scalar that reflects the value of a
> variable for one precise observation, something of the form (which of
course
> doesn't work):
> local a=mother==`j' if member==`k'&group==`i' (meaning: mother etc.
should
> refer to the observation: member==`k'&group==`i')
> I coudn't use something like motherm[_...] becauseI was not using by: ...
.
> What I would like to know if there are more efficient ways of doing this
(I'm
> sure there are!).
>
> Thank you all
>
> ***************************
> Guillermo Cruces
>
> *
> * For searches and help try:
> * http://www.stata.com/support/faqs/res/findit.html
> * http://www.stata.com/support/statalist/faq
> * http://www.ats.ucla.edu/stat/stata/
______________________________________
Universidad Alberto Hurtado
http://www.uahurtado.cl
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
