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add_ucdp_acd() allows you to add UCDP Armed Conflict data to a state-year data frame

Usage

add_ucdp_acd(data, type, issue, only_wars = FALSE)

Arguments

data

state-year data frame

type

the types of armed conflicts the user wants to consider, specified as a character vector. Options include "extrasystemic", "interstate", "intrastate", and "II". "II" is convenience shorthand for "internationalized intrastate". If you want just one (say: "intrastate"), then the type you want in quotes is sufficient. If you want multiple, wrap it in a vector with c().

issue

do you want to subset the data to just different armed conflicts over different types of issues? If so, specify those here as you would with the type argument. Options include "territory", "government", and "both". See Details note in this documentation for what "both" means.

only_wars

subsets the conflict data to just those with intensity levels of "war" (i.e. >1,000 deaths). Defaults to FALSE.

Value

add_ucdp_acd() takes a state-year data frame and returns state-year information from the UCDP Armed Conflict data set (v. 25.1). The variables returned are whether there is an ongoing armed conflict in that year, whether there was an armed conflict episode onset that year, what was the maximum intensity observed that year (if an armed conflict was observed), and a character vector of the associated conflict IDs that year.

Details

Right now, only state-year data are supported.

It's worth saying that "both" in the issue argument should not be understood as equivalent to c("territory","government"). The former is a kind of "AND" (in boolean speak) and is an explicit category in the data. The latter is an "OR" (in boolean speak) and is in all likelihood what you want if you are tempted to specify "both" in the issue argument.

References

Gleditsch, Nils Petter; Peter Wallensteen, Mikael Eriksson, Margareta Sollenberg, and Havard Strand. 2002. "Armed Conflict 1946–2001: A New Dataset." Journal of Peace Research 39(5): 615–637.

Davies, Shawn, Therése PEttersson, Margareta Sollenberg, and Magnus Öberg. 2025. "Organized violence 1989–2024, and the challenges of identifying civilian victims." Journal of Peace Research 62(4): 1223–1240.

Author

Steven V. Miller

Examples



# just call `library(tidyverse)` at the top of the your script.
library(magrittr)
library(dplyr)
#> 
#> Attaching package: ‘dplyr’
#> The following objects are masked from ‘package:stats’:
#> 
#>     filter, lag
#> The following objects are masked from ‘package:base’:
#> 
#>     intersect, setdiff, setequal, union

create_stateyears(system = "gw", subset_years = c(1946:2024)) %>%
 add_ucdp_acd()
#> Joining with `by = join_by(gwcode, year)`
#> # A tibble: 12,507 × 8
#>    gwcode gw_name            microstate  year ucdpongoing ucdponset maxintensity
#>     <dbl> <chr>                   <dbl> <dbl>       <dbl>     <dbl>        <dbl>
#>  1      2 United States of …          0  1946           0         0           NA
#>  2      2 United States of …          0  1947           0         0           NA
#>  3      2 United States of …          0  1948           0         0           NA
#>  4      2 United States of …          0  1949           0         0           NA
#>  5      2 United States of …          0  1950           1         1            1
#>  6      2 United States of …          0  1951           0         0           NA
#>  7      2 United States of …          0  1952           0         0           NA
#>  8      2 United States of …          0  1953           0         0           NA
#>  9      2 United States of …          0  1954           0         0           NA
#> 10      2 United States of …          0  1955           0         0           NA
#> # ℹ 12,497 more rows
#> # ℹ 1 more variable: conflict_ids <chr>

create_stateyears(system = "gw", subset_years = c(1946:2024)) %>%
 add_ucdp_acd(type = 'intrastate', issue = 'government')
#> Joining with `by = join_by(gwcode, year)`
#> # A tibble: 12,507 × 8
#>    gwcode gw_name            microstate  year ucdpongoing ucdponset maxintensity
#>     <dbl> <chr>                   <dbl> <dbl>       <dbl>     <dbl>        <dbl>
#>  1      2 United States of …          0  1946           0         0           NA
#>  2      2 United States of …          0  1947           0         0           NA
#>  3      2 United States of …          0  1948           0         0           NA
#>  4      2 United States of …          0  1949           0         0           NA
#>  5      2 United States of …          0  1950           0         0           NA
#>  6      2 United States of …          0  1951           0         0           NA
#>  7      2 United States of …          0  1952           0         0           NA
#>  8      2 United States of …          0  1953           0         0           NA
#>  9      2 United States of …          0  1954           0         0           NA
#> 10      2 United States of …          0  1955           0         0           NA
#> # ℹ 12,497 more rows
#> # ℹ 1 more variable: conflict_ids <chr>