Data sources and interpretation

contentiousR standardizes country and year keys; it does not make the underlying research designs interchangeable. Cite each source used in an analysis and consult its codebook for definitions, scope, and limitations.

Argument Bundled version and coverage Unit returned Source
GDP: "gapminder" Gapminder v32 Country-year Gapminder
GDP: "fariss" Fariss et al. 2022, latent estimate, 1500–2019 Country-year Dataverse
Population: "wpp" UN World Population Prospects 2024, 1949–2023 Country-year UN Population Division
Population: "nmc" National Material Capabilities v7.0, 1816–2022 Country-year Correlates of War
Population: "fariss" Fariss et al. 2022, latent estimate, 1500–2019 Country-year Dataverse
Military expenditure: "sipri" SIPRI Military Expenditure Database v1.2, 1949–2025 Country-year SIPRI
Military expenditure: "nmc" National Material Capabilities v7.0, 1816–2022 Country-year Correlates of War
Military expenditure: "barnum" Barnum et al. 2025, latent estimate, 1816–2019 Country-year Dataverse
"navco1.3" NAVCO 1.3, 1900–20191 Campaign onset Dataverse
"navco2.1" NAVCO 2.1, 1945–2013 Campaign-year Dataverse
"beissinger" Revolutionary Episodes Dataset, 1900–20142 Episode onset Mark Beissinger
"csra" CSRA Revolutionary Database v1.102, 2000–2024 Episode onset HSE University
"scad" SCAD 3.3, 1990–20173 Country-year Strauss Center
"ucdp_prio" UCDP/PRIO 26.1, 1946–2025 Country-year UCDP
"ucdp_vpp" UCDP VPP 26.1, 1989–2025 Country-year UCDP
"mm" Mass Mobilization, 1990–2020 Country-year Project website
"mmad" MMAD v5.0, 2003–2022 Country-year MMAD
"mec" Major Episodes of Contention, 1955–2018 Episode (global) Article / data
"archigos" Archigos 4.1, 1875–2015 Country-year Archigos
"reign" REIGN, 1921–2021 Country-year REIGN
V-Dem Installed vdemdata release Country-year V-Dem

Licensing

The package’s MIT license applies to the software, not to third-party data. Gapminder and UCDP identify their bundled data as CC BY 4.0; NAVCO 2.1 and MEC are CC0; UN WPP is CC BY 3.0 IGO. Other source files, including NMC, SIPRI, and the Fariss et al. and Barnum et al. estimates, retain their creators’ terms — SIPRI in particular is free to use with attribution but requires separately negotiating a royalty for commercial use. See inst/COPYRIGHTS and verify the applicable terms before redistributing a package build containing those files.


  1. The bundled file contains two records beginning in 1899.↩︎

  2. The bundled file contains two records beginning in 1899.↩︎

  3. Official coverage begins in 1990; one continuing event has a recorded 1989 start.↩︎