Data merge

[Mohamed Abdelrahman]

Dear All,

I am doing a gravity model and I am having problems with merging two data sets, I want me data set to look like that (picture attached).

Now I have a one world data set, with the GDP from 1990 till 2014 and another data set with the population for the same countries and time period.

Could you please tell me how to merge them so that the data set will look like the picture I have attached?

[Friedrich Huebler]

Please give a more precise description of the two datasets that you wish to merge. Even better, share excerpts from both datasets. You can use the dataex package for this, described in section 12 of the FAQ.

[Mohamed Abdelrahman]

I have attached two data sets, I want to merge them so that they will look like the previous photo I have attached, each country against each other (bilateral).

[Friedrich Huebler]

I have attached two data sets, I want to merge them so that they will look like the previous photo I have attached, each country against each other (bilateral).

The picture in post #1 is a screenshot of the Stata Data Editor but the variables don't match the two datasets attached to post #3.

I assume you wish to carry out a 1:1 merge on the variables countrycode and time. This is documented in

help merge

[Mohamed Abdelrahman]

they are the same countries but before sort command, i just need to know if the merge command will list all countries against each other as in the screenshot

[Friedrich Huebler]

i just need to know if the merge command will list all countries against each other as in the screenshot

Did you try what I proposed in post #4?

[Mohamed Abdelrahman]

yes I have applied the following:

use "C:\Users\M.Abdelrahman\Desktop\merg 1.dta", clear
sort countrycode time
save "C:\Users\M.Abdelrahman\Desktop\merg 1.dta", replace
clear
use "C:\Users\M.Abdelrahman\Desktop\merge 2.dta", clear
sort countrycode time
save
save "C:\Users\M.Abdelrahman\Desktop\merge 2.dta", replace
clear
cd "C:\Users\M.Abdelrahman\Desktop"
merge 1:1 countrycode using merge2.dta

but I got the following error
. merge 1:1 countrycode using merge2.dta
variable countrycode does not uniquely identify observations in the master data
r(459);

[Friedrich Huebler]

Indeed, countrycode alone is not sufficient for the merge. Please see what I wrote in post #4.

I assume you wish to carry out a 1:1 merge on the variables countrycode and time.

merge 1:1 countrycode time using merge2.dta

[Mohamed Abdelrahman]

I am sorry, I have read the help page for the merge command but I still cannot figure out what I did wrong, could you please clarify to me ?

[Friedrich Huebler]

Please see post #8.

[Mohamed Abdelrahman]

thank you it worked