Add V-Dem indicators to a state panel — add

Joins V-Dem country-year data onto an existing state panel. The coding system and year range are detected automatically from the panel.

Requires the vdemdata package: remotes::install_github("vdeminstitute/vdemdata")

Usage

add_vdem(panel, vars = NULL)

Arguments

panel: A data frame produced by build_states_panel().
vars: Character vector of V-Dem variable names. If NULL, a default set of democracy, civil liberties, civil society, and rule-of-law indicators is used. See load_vdem_data() for the full default list.

Value

The input panel with V-Dem columns added via left join.

References

Coppedge, M., Gerring, J., Knutsen, C. H., Lindberg, S. I., Teorell, J., Altman, D., Bernhard, M., Fish, M. S., Glynn, A., Hicken, A., et al. (2025). V-Dem [Country-Year/Country-Date] Dataset v15. Varieties of Democracy.

Examples

if (requireNamespace("vdemdata", quietly = TRUE)) {
panel <- build_states_panel(1990, 2010, coding_system = "cow") |>
  add_vdem(vars = c("v2x_polyarchy", "v2x_libdem", "v2x_rule"))
}