Regarding generating year-sum for each variable

[Woosung Kim]

Dear,

I have a question.

I have a panel data looks like below.

country  year   x     y
"Indonesia" 1990  24   36
"Indonesia" 1991  28   22
"Korea"       1990  38   27
"Korea"       1991  42   73
"China"       1990  124 458
"China"       1991  12   24

I'd like to generate sum for each year of each variable from 1990 to 2014 and want to plot them.
Would you help me to do these?

Many Thanks,

[Clyde Schechter]

collapse (sum) x y, by(year)
graph twoway line x y year, sort

[Woosung Kim]

Thanks a lot. It helps me.
Best,

[Nick Cox]

You could also go

egen sum_x = total(x), by(year)
egen tag = tag(year)
line sum_x year if tag, sort

and similarly for other variables.