These are the Correlates of War state system membership data.
Format
A data frame with 243 observations on the following 10 variables.
stateabba character vector for the state abbreviation
ccodea numeric vector for the Correlates of War country code
statenmea character vector for the state name
styearthe start year in the system
stmonththe start month in the system
stdaythe start day in the system
endyearthe end year in the system
endmonththe end month in the system
enddaythe end day in the system
versiona version identifier
Details
Data are provided "as-is" with no additional re-cleaning before inclusion into this data set.
References
Correlates of War Project. 2017. "State System Membership List, v2016." Online, https://correlatesofwar.org/data-sets/state-system-membership/