Create state-years from state system membership data
Source:R/create_stateyears.R
create_stateyears.Rd
create_stateyears()
allows you to generate state-year data from
either the Correlates of War (CoW
) state system membership data or the
Gleditsch-Ward (gw
) system membership data. The function leans on internal
data provided in the package.
Arguments
- system
a character specifying whether the user wants Correlates of War state-years ("cow") or Gleditsch-Ward ("gw") state-years. Correlates of War is the default.
- mry
optional, defaults to TRUE. If TRUE, the function extends the script beyond the most recent system membership updates to include observation to the most recently concluded calendar year. For example, the Gleditsch-Ward data extend to the end of 2017. When
mry == TRUE
, the function returns more recent years (e.g. 2018, 2019) under the assumption that states alive at the end of 2017 are still alive today. Use with some care.- subset_years
and optional character vector for subsetting the years returned to just some temporal domain of interest to the user. For example,
c(1816:1820)
would subset the data to just all state-years in 1816, 1817, 1818, 1819, and 1820. Be advised that it's easiest to subset the data after the full universe of state-year data have been created. This means you could, if you choose, effectively overwritemry = TRUE
with this argument since themry
argument is applied at the expansion of the state system data into state-year data.
Value
create_stateyears()
takes state system membership data provided
by either Correlates of War or Gleditsch-Ward and returns a simple state-year
data frame.
References
Miller, Steven V. 2019. ``Create Country-Year and (Non)-Directed Dyad-Year Data With Just a Few Lines in R'' http://svmiller.com/blog/2019/01/create-country-year-dyad-year-from-country-data/
Examples
# CoW is default, will include years beyond 2016 (most recent CoW update)
create_stateyears()
#> # A tibble: 17,121 × 3
#> ccode statenme year
#> <dbl> <chr> <int>
#> 1 2 United States of America 1816
#> 2 2 United States of America 1817
#> 3 2 United States of America 1818
#> 4 2 United States of America 1819
#> 5 2 United States of America 1820
#> 6 2 United States of America 1821
#> 7 2 United States of America 1822
#> 8 2 United States of America 1823
#> 9 2 United States of America 1824
#> 10 2 United States of America 1825
#> # ℹ 17,111 more rows
# Gleditsch-Ward, include most recent years
create_stateyears(system="gw")
#> # A tibble: 18,637 × 3
#> gwcode statename year
#> <dbl> <chr> <int>
#> 1 2 United States of America 1816
#> 2 2 United States of America 1817
#> 3 2 United States of America 1818
#> 4 2 United States of America 1819
#> 5 2 United States of America 1820
#> 6 2 United States of America 1821
#> 7 2 United States of America 1822
#> 8 2 United States of America 1823
#> 9 2 United States of America 1824
#> 10 2 United States of America 1825
#> # ℹ 18,627 more rows
# Gleditsch-Ward, don't include most recent years
create_stateyears(system="gw", mry=FALSE)
#> # A tibble: 17,767 × 3
#> gwcode statename year
#> <dbl> <chr> <int>
#> 1 2 United States of America 1816
#> 2 2 United States of America 1817
#> 3 2 United States of America 1818
#> 4 2 United States of America 1819
#> 5 2 United States of America 1820
#> 6 2 United States of America 1821
#> 7 2 United States of America 1822
#> 8 2 United States of America 1823
#> 9 2 United States of America 1824
#> 10 2 United States of America 1825
#> # ℹ 17,757 more rows