add_cow_trade: Add Correlates of War trade data to a data frame

View source: R/add_cow_trade.R

add_cow_tradeR Documentation

Add Correlates of War trade data to a data frame


add_cow_trade() allows you to add Correlates of War trade data to your (dyad-year, leader-year, leader-dyad-year, state-year) data frame





a data frame with appropriate peacesciencer attributes


For the dyad-year (and leader-dyad-year) data, there must be some kind of information loss in order to work within the limited space available to this package. This package loads a truncated version of the data in which the trade values are rounded to three decimal points in order to greatly reduce the disk space for this package. I do not think this to be terribly problematic, though I admit I do not like it. If this is a problem for your research question, you may want to consider not using this function for dyad-year or leader-dyad-year data.

Be mindful that the data are fundamentally state-year or dyad-year and that extensions to leader-level data should be understood as approximations for leaders (leader-dyads) in a given state-year (dyad-year).


add_cow_trade() takes a (dyad-year, leader-year, leader-dyad-year, state-year) data frame and adds information about the volume of trade in that given dyad-year or state-year. For the state-year (leader-year) data, these are minimally the sum of all imports and the sum of all exports. For dyad-year (leader-dyad-year) data, this function returns the value of imports in current million USD in the first country from the second country (and vice-versa) along with their "smooth" equivalents.


Steven V. Miller


Barbieri, Katherine, Omar M. G. Keshk, and Brian Pollins. 2009. "TRADING DATA: Evaluating our Assumptions and Coding Rules." Conflict Management and Peace Science. 26(5): 471-491.


# just call `library(tidyverse)` at the top of the your script
# The function below works, but depends on running `download_extdata()` beforehand.
# cow_ddy %>% add_cow_trade()

create_stateyears() %>% add_cow_trade()

peacesciencer documentation built on March 24, 2022, 5:06 p.m.