These contain an abbreviated version of the "master records" for the Correlates of War direct contiguity data. Data contain a few cosmetic changes to assist with some functions downstream from it.
Format
A data frame with 2025840 observations on the following 4 variables.
ccode1a numeric vector for the Correlates of War state code for the first state
ccode2a numeric vector for the Correlates of War state code for the second state
conttypea numeric vector for the contiguity relationship
beginthe year-month when this contiguity relationship begins (YYYYMM)
endthe year-month when this contiguity relationship ends (YYYYMM)
Details
The "master record" provided by the Correlates of War is "non-directed." I make these data "directed" for convenience.
For clarity, the contiguity codes range from 1 to 5. 1 = direct land contiguity. 2 = separated by 12 miles of water or fewer (a la Stannis Baratheon). 3 = separated by 24 miles of water or fewer (but more than 12 miles). 4 = separated by 150 miles of water or fewer (but more than 24 miles). 5 = separated by 400 miles of water or fewer (but more than 150 miles). Cases of separation by more than 400 miles of water are not included in the master record (but are easily discerned based on complete dyad-year data).