Re: st: Problems with expand og reverting to original dataset

[Grethe Søndergaard <dkstatstata@gmail.com>]

Thank you for your answers

@ Nick Cox: I have tried to run bysort mother_id father_id
(birth_date) : gen diff = birth_date[2] -birth_date[1]. However, an
error message appear: "factor variables and time-series operators not
allowed". Can I solve this problem - by somehow changing the type of
variable that birth_date is?

@ Ada Ma: My dataset consists of more than two siblings per family
(one line for each person). I am not sure how to find out which
siblings to be included in the dataset, if more than two siblings are
being compared. E.g. a family consists of children age 1, 4, and 8 (so
who should stay in the dataset). So that is why I choose only to
include persons with one siblings.



2011/1/20 Nick Cox <njcoxstata@gmail.com>:
> Nick
>
> On Thu, Jan 20, 2011 at 1:28 PM, Ada Ma <heu034@googlemail.com> wrote:
>> How does your original dataset looks like?
>>
>> One line of data per person or one line of data per pair of siblings?
>> Do you always have 2 siblings or do you have more than 2 siblings?
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