add_rugged_terrain() allows you to add information, however crude,
about the "ruggedness" of a state's terrain to your (dyad-year, leader-year,
leader-dyad-year, state-year) data.
add_rugged_terrain(data)add_rugged_terrain() takes a (dyad-year, leader-year, leader-dyad-year,
state-year) data frame, whether the primary state identifiers are from the
Correlates of War system or the Gleditsch-Ward system, and returns
information about the "ruggedness" of the state's terrain. The two indicators
returned are the "terrain ruggedness index" calculated by Nunn and Puga
(2012) and a logarithmic transformation of how mountainous the state is
(as calculated by Gibler and Miller, 2014). The dyad-year (leader-dyad-year)
data get four additional columns (i.e. both indicators for both states in the
dyad) whereas the state-year data get just the two additional columns.
a data frame with appropriate peacesciencer attributes
Steven V. Miller
Please see the information for the underlying data rugged, and the
associated R script in the data-raw directory, to see how these data
are generated. Importantly, these data are time-agnostic and move slowly.
We're talking about geography here. Both data sets benchmark around
1999-2000 and it's a leap of faith to use these data for comparisons across
the entirety of the Correlates of War or Gleditsch-Ward system membership.
Every use of data of these types have been either cross-sectional snapshots
or for making state-to-state comparisons after World War II (think of your
prominent civil war studies here). Be mindful about what you expect to get
from these data.
The data have both Gleditsch-Ward codes and Correlates of War codes. The
merge it makes depends on what you declare as the "master" system at the top
of the pipe (e.g.. in create_dyadyears() or
create_stateyears()). If, for example, you run
create_stateyears(system="cow") and follow it with
add_gwcode_to_cow(), the merge will be on the Correlates of War codes
and not the Gleditsch-Ward codes. You can see the script mechanics to see how
this is achieved.
Fearon, James D., and David Laitin, "Ethnicity, Insurgency, and Civil War" American Political Science Review 97: 75–90.
Gibler, Douglas M. and Steven V. Miller. 2014. "External Territorial Threat, State Capacity, and Civil War." Journal of Peace Research 51(5): 634-646.
Nunn, Nathan and Diego Puga. 2012. "Ruggedness: The Blessing of Bad Geography in Africa." Review of Economics and Statistics. 94(1): 20-36.
Riley, Shawn J., Stephen D. DeGloria, and Robert Elliot. 1999. "A Terrain Ruggedness Index That Quantifies Topographic Heterogeneity,” Intermountain Journal of Sciences 5: 23–27.
# \donttest{
# just call `library(tidyverse)` at the top of the your script
library(magrittr)
cow_ddy %>% add_rugged_terrain()
create_stateyears() %>% add_rugged_terrain()
create_stateyears(system = "gw") %>% add_rugged_terrain()
# }
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