<>
Check this very carefully:
*************
clear*
set obs 102
set seed 12345
gen id=_n
forv i=1/48{
gen byte w`i'=runiform()<0.5
}
reshape long w, i(id) j(week)
l in 1/40, noobs
tsset id week
bysort id (week): gen byte success= /*
*/ (L3.w==0)*(L2.w==0)*(L.w==0)*(w==0)
bysort id (week): gen byte successtime= /*
*/ cond((_n<4), 0, success*(L3.week))
l in 1/40, noobs
*************
HTH
Martin
-----Ursprüngliche Nachricht-----
Von: [email protected]
[mailto:[email protected]] Im Auftrag von Morten Vejs
Willert
Gesendet: Donnerstag, 24. September 2009 14:12
An: [email protected]
Betreff: st: identifying spells in panel data
In relation to performing a cox regression, I am looking for a way to
identify spells in a dataset containing longitudinal panel data of 48
week-by-week registrations on absenteeism from work.
The dataset is in wide format. For each participant(=id) there are 48
variables (one per week) containing either the value 0 (=working) or
the value 1 (=absent from work). The week-by-week variables are named
consecutively w1, w2, w3, ... w48, as illustrated below:
id w1 w2 w3 w4 w5 w6 ..... w48
1 1 1 1 0 0 0 0
2 1 0 0 0 0 0 0
3 1 1 1 1 1 0 0
4 0 0 0 0 0 0 0
...
102 1 1 1 1 0 0 0
I am interested in determining when a participant has had a spell of
four consecutive weeks working - so in my dataset I want to identify
spells of 4 consecutive 0's, when combing through the variable w1 to
w48 - and I want to generate two new variables: 'success' describing
if the participant has had such a spell (values 0 or1), and
'successtime' denoting the first week of the identified spells (values
1 to 45).
I have tried to use the command -spell- to achieve this, but with no
success. Does anyone have a solution to this problem?
Best regards
Morten Vejs Willert
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