add_contiguity()
allows you to add Correlates of War contiguity
data to a dyad-year or state-year data frame.
add_contiguity(data)
a dyad-year data frame (either "directed" or "non-directed") or a state-year data frame
add_contiguity()
takes a dyad-year data frame and adds information
about the contiguity relationship based on the "master records" for the
Correlates of War direct contiguity data (v. 3.2). If the data are dyad-year, the function
returns the lowest contiguity type observed in the dyad-year (if contiguity is observed at all).
If the data are state-year, the data return the total number of land and sea borders calculated
from these master records.
The contiguity codes in the dyad-year data range from 0 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).
Importantly, 0 are the dyads that are not contiguous at all in the CoW contiguity data. This is a conscious decision on my part as I do not think of the CoW's contiguity data as exactly ordinal. Cross-reference CoW's contiguity data with the minimum distance data in this exact package to see how some dyads that CoW codes as not contiguous are in fact very close to each other, sometimes even land-contiguous. For example, Zimbabwe and Namibia are separated by only about a few hundred feet of water at that peculiar intersection of the Zambezi River where the borders of Zambia, Botswana, Namibia, and Zimbabwe meet. There is no contiguity record for this in the CoW data. There are other cases where contiguity records are situationally missing (e.g. India-Bangladesh, and Bangladesh-Myanmar in 1971) or other cases where states are much closer than CoW's contiguity data imply (e.g. Pakistan and the Soviet Union were separated by under 30 kilometers of Afghani territory). The researcher is free to recode these 0s to be, say, 6s, but this is why peacesciencer does not do this.
For additional clarity, the "master records" produce duplicates for cases when the contiguity relationship changed in a given year. This function returns the *minimum* contiguity relationship observed in that given year. There should be no duplicates in the returned output.
Stinnett, Douglas M., Jaroslav Tir, Philip Schafer, Paul F. Diehl, and Charles Gochman (2002). "The Correlates of War Project Direct Contiguity Data, Version 3." Conflict Management and Peace Science 19 (2):58-66.
# NOT RUN {
# }
# NOT RUN {
# just call `library(tidyverse)` at the top of the your script
library(magrittr)
cow_ddy %>% add_contiguity()
create_stateyears() %>% add_contiguity()
# }
# NOT RUN {
# }
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