igo_state_membership: Extract IGO membership records for states

In igoR: Access the Intergovernmental Organizations ('IGO') Database

Extract IGO membership records for states

Description

Extracts IGO membership records for one or more states and years.

Usage

igo_state_membership(state, year = NULL, status = "Full Membership")

Arguments

state	A state name or code, or a vector of names or codes, as specified in states2016.
year	An integer or vector of years to assess. If NULL, the latest available year for each state is used.
status	A character vector of membership statuses to extract. See igo_year_format3 for valid statuses.

Value

A data.frame with one row per matching state, year, IGO and membership status.

Source

Codebook Version 3 IGO Data for the full reference.

References

Pevehouse, J. C., Nordstrom, T., McManus, R. W. & Jamison, A. S. (2020). Tracking organizations in the world: The Correlates of War IGO Version 3.0 data sets. Journal of Peace Research, 57(3), 492–503. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1177/0022343319881175")}.

See Also

igo_year_format3, igo_search_states(), states2016.

Other membership functions: igo_dyadic(), igo_members()

Examples

# Memberships on two different dates.
igo_state_membership("Spain", year = 1850)
igo_state_membership("Spain", year = 1870)
igo_state_membership("Spain", year = 1880:1882)

# Use the latest available year.
igo_state_membership("ZAN")[, 1:7]

# Search by state code.
igo_state_membership("2", year = 1865)

# Extract multiple membership statuses.
igo_state_membership("kosovo", status = c(
  "Associate Membership", "Observer",
  "Full Membership"
))

# Vectorized search.
igo_state_membership(c("usa", "spain"), year = 1870:1871)

# Use the countrycode package to add codes.
if (requireNamespace("countrycode", quietly = TRUE)) {
  library(countrycode)
  IT <- igo_state_membership("Italy", year = 1880)
  IT$iso3c <- countrycode(IT$ccode, origin = "cown", destination = "iso3c")
  head(IT)
}

igoR documentation built on June 24, 2026, 9:07 a.m.