Re: st: Identifying the second occurrence of event in panel data

[Maarten Buis <maartenlbuis@gmail.com>]

On Wed, Aug 14, 2013 at 11:52 AM, Daniel Sage wrote:
>
> I have panel data and wish to record the second occurrence of an event.  The event is unemployment.
> I am able to identify the first occurrence of unemployment using the following:
>
> by pid (wav), sort: gen noccur = sum(unemployed)
> by pid: gen byte first = noccur == 1 & noccur[_n-1] != noccur
>
> But I am unsure how to identify the second occurrence.

*------------------ begin example ------------------
clear

input id year unemployed
1 1 0
1 2 1
1 3 1
1 4 0
1 5 0
1 6 0
1 7 1
1 8 1
1 9 1
1 10 1
2 1 0
2 2 1
2 3 1
2 4 0
2 5 0
2 6 0
2 7 1
2 8 1
2 9 1
2 10 1
end

tsset id year
bys id (year): gen change = unemployed == 1 & L.unemployed == 0 if _n >1

bys id (year):gen spell = sum(change) if change == 1
list, sepby(id)
*------------------- end example -------------------
* (For more on examples I sent to the Statalist see:
* http://www.maartenbuis.nl/example_faq )

Hope this helps,
Maarten

---------------------------------
Maarten L. Buis
WZB
Reichpietschufer 50
10785 Berlin
Germany

http://www.maartenbuis.nl
---------------------------------
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