Author: Andreas Beger
Date: 2025-08-25

# G&W and COW country code differences

#### Andreas Beger

#### 2025-08-25

The COW and G&W state system lists generally have high overlap, but there are differences in states start and end dates, and also some differences in which numeric code is used for a particular states. Some notable code differences for post-WW2 states to look out for when trying to merge datasets with/from COW to G&W coding are:

Case | G&W | COW
--- | --- | ---
Germany after 1990 unification | continue 260 | 255
Yemen after 1990 unification | continue 678 | 679
Serbia after 2006 dissolution of Serbia & Montenegro | 340 | continue 345
Kiribati | 970 | 946
Nauru | 971 | 970
Tuvalu | 973 | 947
Tonga | 972 | 955