Keith's answer is in essence identical to mine.
But to me such a solution is still less than ideal. You would be much better off, I guess, reshaping your data to long. That will make most things you might want to do with such data much easier.
reshape long x, i(ID) j(year)
bysort ID (x year) : gen firstzero = year if x[1] == 0
If you really want the present data structure, you can
reshape wide
to get it back.
Nick
[email protected]
Man Jia
Thanks very much for your help! It works well. I appreciate it.
Keith Dear
>>You could do it like this:
>>
>>gen int firstzero=.
>>forval y=1995/2002 {
>> replace firstzero=`y' if firstzero==. & x`y'==0
>>}
>>>I have a data set like this:
>>>-------------------------------------------------------------------
>>>ID,x1995, x1996, x1997, x1998, x1999, x2000, x2001, x2002
>>>
>>> 1 1 0 1 1 0 1 0
>>> 0
>>> 2 0 0 0 0 1 0 0
>>> 0
>>> 3 1 1 0 1 0 0 0
>>> 0
>>>---------------------------------------------------------------------
>>>I want to find out for each observation the first year when the value
>>>of the variable x becomes 0.
>>>
>>>For example, for observation 1, the first year x becomes 0 is 1996. For
>>>observation 2 and 3, 1995 and 1997 respectively.
>>>
>>>I'm not sure how to let the "searching the first 0" loop stop when x
>>>becomes 0. I checked STATA's help; I was wondering if the command
>>>"continue" will work here. Could someone give me some hints about this?
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