add_nmc: Add Correlates of War National Military Capabilities Data

In peacesciencer: Tools and Data for Quantitative Peace Science Research

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)

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.

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.

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.

Author(s)

Steven V. Miller

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.

Examples

# just call `library(tidyverse)` at the top of the your script
library(magrittr)

cow_ddy %>% add_nmc()

create_stateyears() %>% add_nmc()

peacesciencer documentation built on Aug. 8, 2025, 6:13 p.m.