Summing data by year and country

[Asim Risljanin]

Good evening,

I have data that looks sort of like this example:

Year	Host Country	Origin Country	Refugees
2000	Afghanistan	Lebanon	20
2000	Afghanistan	Syria	30
2001	Afghanistan	Lebanon	40
2001	Afghanistan	Syria	60
2001	Afghanistan	Palestine	20
2000	Germany	Albania	5
2000	Germany	Algeria	10
2000	Germany	Syria	50

Etc. for a dataset with thousands of rows of countries and years.


And i would like to remove the distinction of the origin countries so that the refugees are added up like so (using the example):

Year	Host Country	Refugees total
2000	Afghanistan	50
2001	Afghanistan	120
2000	Germany	65

Are there any commands i could use to combine the refugee data per year/host-country group?

[Clyde Schechter]

collapse (sum) refugees, by(host_country year)

-collapse- is one of the "bread and butter" commands in Stata that everyone needs to know about to use Stata effectively. I suggest reading the Getting Started [GS] and User's Guide [U] volumes of the PDF manuals that come with your Stata installation in their entirety. While you won't remember everything, they will introduce you to the basic commands that are commonly used and familiarize you with Stata's general approach to data management and analysis. With that time invested, you will in most situations grasp which commands are likely to figure in the solution to your problem, and then you can refer to the help files for the unremembered details of syntax.

In the future, before posting example data, import it to Stata, and then use the -dataex- command to post it. You can get the -dataex- command by running -ssc install dataex-, and you can read the simple instructions for using it by running -help dataex-. Using -dataex- to post example data makes it possible for those who want to help you to create a faithful replica of your Stata example with a simple copy/paste operation.

[Asim Risljanin]

Thank you! This solved my problem. I knew of the collapse function but i didn't fully understand i could use it like that. Learned something new today.
I'll take your advice and look more into the bread and butter commands of Stata.