add_nmc: Add Correlates of War National Military Capabilities Data
Description
add_nmc() allows you to add the Correlates of War National Material
Capabilities data to your data.
Usage
add_nmc(data, keep)
Value
add_nmc() takes a (dyad-year, leader-year, leader-dyad-year,
state-year) data frame and adds information about the national material
capabilities for the state or two states in the dyad in a given year. If the
data are dyad-year (or leader-dyad-year), the function adds 12 total columns
for the first state (i.e. ccode1) and the second state (i.e.
ccode2) for all estimates of national military capabilities provided
by the Correlates of War project. If the data are state-year (or leader-year),
the function returns six additional columns to the original data that contain
that same information for a given state in a given year.
Arguments
data
a data frame with appropriate peacesciencer attributes
keep
an optional parameter, specified as a character vector, about
what capability estimates the user wants to return from this function. If not
specified, everything from the underlying capabilities data is returned.
Author
Steven V. Miller
Details
Be mindful that the data are fundamentally state-year and that extensions to
leader-level data should be understood as approximations for leaders in a
given state-year.
The keep argument must include one or more of the capabilities estimates
included in cow_nmc. Otherwise, it will return an error that it cannot
subset columns that do not exist.
References
Singer, J. David, Stuart Bremer, and John Stuckey. (1972).
"Capability Distribution, Uncertainty, and Major Power War, 1820-1965." in
Bruce Russett (ed) Peace, War, and Numbers, Beverly Hills: Sage, 19-48.
Singer, J. David. 1987. "Reconstructing the Correlates of War Dataset on
Material Capabilities of States, 1816-1985."
International Interactions 14(1): 115-32.