Re: st: Fill in values for year in an unbalanced panel with known order

[Nick Cox <njcoxstata@gmail.com>]

Fine; but -missing()- is a function, not an option.

Nick

On Tue, Oct 23, 2012 at 5:25 PM, Fernando Luco
<flucoestatalist@gmail.com> wrote:
> Thanks Nick, it worked perfectly. I didn't think about using the
> 'missing()' option.
>
> Fernando
>
> On Tue, Oct 23, 2012 at 11:19 AM, Nick Cox <njcoxstata@gmail.com> wrote:
>> This is a variation on a standard problem, on which see
>>
>> FAQ     . . . . . . . . . . . . . . . . . . . . . . . Replacing missing values
>>         . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N. J. Cox
>>         1/12    How can I replace missing values with previous or
>>                 following nonmissing values or within sequences?
>>                 http://www.stata.com/support/faqs/data-management/
>>                 replacing-missing-values/
>>
>> I suggest
>>
>> sort id, stable
>> by id: replace year = cond(month == 1, year[_n-1] + 1, year[_n-1]) if
>> missing(year)
>>
>> Nick
>>
>> On Tue, Oct 23, 2012 at 5:07 PM, Fernando Luco
>> <flucoestatalist@gmail.com> wrote:
>>
>>> I'm trying to fill in the year of observations for which I know the
>>> month and because of the order, I have no doubt about the year.
>>> However, the year was not recorded. In particular, the data looks as
>>> follows
>>>
>>> id year month
>>> 1 1988 5
>>> 1 . 6
>>> 1 . 7
>>> 1 . 8
>>> 1 . 9
>>> 1 . 10
>>> 1 . 11
>>> 1 . 12
>>> 1 . 1
>>> 1 1989 2
>>> 1 1989 3
>>> 1 . 4
>>> 2 . 3
>>> 2 1989 4
>>> 2 1989 5
>>> 2 . 6
>>> 2 . 7
>>> 2 . 8
>>> 2 1989 9
>>> 2 . 10
>>> 2 . 11
>>> 2 . 12
>>> 2 . 1
>>> 2 1990 2
>>> 2 . 3
>>>
>>> So, it is an unbalanced panel, that for each id might start and end at
>>> a different year month combination, and I know that the order of the
>>> observations within id is correct, so I'm sure that the first
>>> observation for id==2 is of 1989 while the second observation that has
>>> id==2 and month==3 (the last observation in the example) corresponds
>>> to 1990. The main complication is that for some people I might have a
>>> gap of more than one year between observations, which has made things
>>> difficult. I would like to use the structure of the data to fill in
>>> the data for year.
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