Re: st: generating new observations

[David Kantor <kantor.d@att.net>]

At 12:45 PM 3/29/2006, Kremena wrote:
> Hi,
>
> I have a data set with the following variables:
>
> importer     exporter     commoditycode   tradevalue
>
> Belgium      Argentina    1               123
> Belgium      Argentina    2               456
> Luxemburg    Argentina    1               789
> Luxembourg   Argentina    3               147
>
> I want to generate new observations such that importer is Belgium-Luxembourg
> and tradevalue is the combined trade value for the two countries for the
> respective commodity.
>
> Can someone tell me how I can do that?
> [...]
You can do...

collapse (sum) tradevalue , by(commoditycode)

This will sum to the level of commoditycode, regardless of importer 
or exporter (and it won't create a combined importer identifier).  If 
you want specific groups of importers or importer/exporter 
combinations, you will need to do that in advance, creating another 
variable, and then put that variable into the by() option.

HTH
Good luck.
--David

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