These are version 6.0 of the Correlates of War National Military Capabilities data. Data omit the state abbreviation and version identifier for consideration.

## Usage

cow_nmc

## Format

A data frame with 15171 observations on the following 9 variables.

ccode

a numeric vector for the Correlates of War country code

year

the year

milex

an estimate of military expenditures (in thousands). See details section for more.

milper

an estimate of the size of military personnel (in thousands) for the state

irst

an estimate of iron and steel production (in thousands of tons)

pec

an estimate of primary energy consumption (thousands of coal-ton equivalents)

tpop

an estimate of the total population size of the state (in thousands)

upop

an estimate of the urban population size of the state (in thousands). See details section for more.

cinc

The Composite Index of National Capability ("CINC") score. See details section for more.

## Details

The user will want to be a little careful with how some of these data are used, beyond the typical caveat about how difficult it is to pin-point how many thousands of coal-tons a state like Baden was producing in the 19th century.

First, military expenditures are denominated in British pounds sterling for observations between 1816 and 1913. The observations from 1914 and beyond are denominated in current United States dollars. This is according to the manual.

Second, urban population size is an estimate based on, well, an estimate of the size of the population living in an area with 100,000 or more people.

Third, the Composite Index of National Capability score is calculated as each state's world share of each of the six composite indicators also included in the data in a given year. It theoretically is bound between 0 and 1. A state with a 1 is 100% responsible for 1) all of the military expenditures in the world, 2) is the only state with a military, 3) does all the iron and steel production, 4) all the world's primary energy consumption, and 5) is the only state in the world with a population and an urban population. Incidentally, the maximum scores observed in the data belong to the United States in 1945.

## 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: 115-32.