Try this:
egen byte n1 = sum(year==1970) , by(countrycode)
assert n1==1 // make sure only one per country
drop n1
gen int temp1 = gdp if year==1970
egen int gdp1970 = max(temp1) by(countrycode)
drop temp1
gen int diff = gdp1970 -gdp
I assumed that int is a good type for gdp.
Also, the first part assures that there is exactly one case with year==1970
per country. You could be a bit more general and assure that there is at
most one case (assert n1<=1).
Maybe there is some other obvious solution I've overlooked.
I hope this helps.
-- David
At 02:14 PM 3/1/2004 -0500, AmBush (Kakatua Kutta) wrote:
countrycode year gdp
BAN 1960 65
BAN 1965 75
BAN 1970 85
CAN 1960 25
CAN 1965 35
CAN 1970 45
Dear Stata users,
Lets say I have the above data set. I want to create a variable which
measures the difference between the gdp in year 1970 and gdp in 1965 for
each country. That is if "diff" is the new variable it would be diff =
gdp(1970)-gdp (1965) for each country.
I am a new user and already spent hours on this. I would much appreciate
your help.
Thanks in advance
AmBush
[...]
David Kantor
Institute for Policy Studies
Johns Hopkins University
[email protected]
410-516-5404
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