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Load population data

Source: R/load_population_data.R
load_population_data.Rd

Loads country-year population data from one of three sources included with the package.

Usage

load_population_data(
  start_year = 1945,
  end_year = 2019,
  dataset = c("wpp", "nmc", "fariss"),
  coding_system = c("cow", "gw")
)

Source

UN WPP: United Nations, Department of Economic and Social Affairs, Population Division (2024). World Population Prospects 2024. https://population.un.org/wpp/

NMC: Singer, J. David, Bremer, Stuart & Stuckey, John (1972). Capability Distribution, Uncertainty, and Major Power War, 1820-1965. National Material Capabilities v7.0. https://correlatesofwar.org/data-sets/national-material-capabilities/

Fariss: Fariss, C.J., Anders, T., Markowitz, J.N., & Barnum, M. (2022). New estimates of over 500 years of historic GDP and population data. Journal of Conflict Resolution, 66(3), 553-591.

Arguments

start_year

Integer. First year to include.

end_year

Integer. Last year to include.

dataset

Character. Dataset to load:

"wpp"

UN World Population Prospects, total population in thousands. Coverage: 1949-2023.

"nmc"

Correlates of War National Material Capabilities v7.0 (abridged): total population (nmc_tpop) and urban population (nmc_upop), both in thousands. Coverage: 1816-2022.

"fariss"

Latent population estimates (Fariss, Anders, Markowitz & Barnum 2022). Coverage: 1500-2019.

coding_system

Character. Country coding system: "cow" or "gw".

Value

A country-year data frame. Columns differ by dataset, each prefixed with the source's dataset key:

wpp: cow/gw, year, wpp_pop.

nmc: cow/gw, year, nmc_tpop, nmc_upop.

fariss: cow/gw, year, fariss_pop.

Details

The bundled UN WPP extract has three rows for some China country-years: a combined mainland+Hong Kong+Macao+Taiwan figure, a mainland-only figure, and a Hong Kong-only figure, all of which matched COW code 710 during country-name conversion upstream. The mainland-only figure is consistently the median of the three, so wpp_pop is computed as the median pop value within each cow-year group; for every other country-year (a single row) this is a no-op.

NMC's -9 missing-data sentinel is recoded to NA in nmc_tpop and nmc_upop.

fariss_pop is the model's own latent-scale estimate, taken directly from the "latent_pop" rows of the replication file. Its absolute units are not independently verified here; consult Fariss et al. (2022) before using it outside of relative/comparative analysis.

References

United Nations, Department of Economic and Social Affairs, Population Division. (2024). World Population Prospects 2024. https://population.un.org/wpp/

Fariss, C. J., Anders, T., Markowitz, J. N., & Barnum, M. (2022). New estimates of over 500 years of historic GDP and population data. Journal of Conflict Resolution, 66(3), 553-591. doi:10.1177/00220027211054432

Singer, J. D., Bremer, S., & Stuckey, J. (1972). Capability distribution, uncertainty, and major power war, 1820-1965. In B. Russett (Ed.), Peace, War, and Numbers (pp. 19-48). Sage.

Singer, J. D. (1988). Reconstructing the Correlates of War dataset on material capabilities of states, 1816-1985. International Interactions, 14, 115-132.

Examples

pop_wpp <- load_population_data(1990, 2015, dataset = "wpp", coding_system = "cow")

pop_nmc <- load_population_data(1900, 2015, dataset = "nmc", coding_system = "cow")