st: RE: RE: Creating new observations

["Nick Cox" <n.j.cox@durham.ac.uk>]

As Martin says, you can do this, but it is not Stataish. 

Stata is not best used as if it were a spreadsheet program, in which you
can tuck all sorts of derivative data and results somewhere else as
extra observations. 

If you do this in Stata, you then have to remember to exclude the new
observations you have created from subsequent commands to avoid double
counting. 

It's better to think in terms of new variables, not new observations. 

Nick 
n.j.cox@durham.ac.uk 

Martin Weiss

This can be done, but is unusual and rare:

***********
clear*

inp str1 Country	byte(Income Population)
A			5				5
B			3				3
N			3				3
end

set obs `=_N+1'


replace Country=Country[1]+"+"+Country[2] in l
replace Income=Income[1]+Income[2] in l
replace Population=Population[1]+Population[2] in l

list, noo
***********

Ida Johnsson

I am new to Stata and have the following problem. How do I create new  
observations if I have panel data, for example

Country		Income			Population
A			5				5
B			3				3
...			...				...
...			...				...
...			...				...
...			...				...
N			3				3


and want to add observations that are grouped values for certain  
countries, for example

Country		Income			Population
A			5				5
B			3				3
...			...				...
...			...				...
...			...				...
...			...				...
N			3				3
A+B			8				8


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