Convert CoW state data to country-year panel data.

1-convert-cow-states-to-country-year.R

library(tidyverse)

States <- read_csv("~/Dropbox/data/COW/states/states2011.csv")

# Create a PDF of state-years. ----------
# States data nominally end in 2011, so let's fudge that.

States %>%
  mutate(endyear = ifelse(endyear == 2011, 2015, endyear)) %>%
  rowwise() %>%
  mutate(year = list(seq(styear, endyear))) %>%
  ungroup() %>%
  unnest() %>%
  arrange(ccode, year) %>%
  select(ccode, year) %>%
  distinct(ccode, year) -> CYs
  
  CYs