add_sdp_gdp: Add (Surplus and Gross) Domestic Product Data

View source: R/add_sdp_gdp.R

add_sdp_gdpR Documentation

Add (Surplus and Gross) Domestic Product Data


add_sdp_gdp() allows you to add estimated GDP and "surplus" domestic product data from a 2020 analysis published in International Studies Quarterly by Anders, Fariss, and Markowitz.





a data frame with appropriate peacesciencer attributes


The function leans on attributes of the data that are provided by one of the "create" functions. Make sure a recognized function (or data created by that function) appear at the top of the proverbial pipe. Users will also want to note that the underlying function access two different data sets. It appears that the results published in the International Studies Quarterly used Correlates of War classification, but a follow-up repository on Github uses Gleditsch-Ward classification. The extent to which these estimates are generated by simulation, it does mean the estimates will be slightly different across both data sets even for common observations (e.g. the United States in 1816).

Because these are large nominal numbers, the estimates have been log-transformed. Users can always exponentiate these if they choose. Researchers can use these data to construct reasonable estimates of surplus GDP per capita, but must exponentiate the underlying variables before doing this.

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


add_sdp_gdp() takes a (dyad-year, leader-year, leader-dyad-year, state-year) data frame and adds information about the estimated gross domestic product (in 2011 USD) for that year, the estimated population in that year, the GDP per capita in that year, and what Anders, Fariss and Markowitz term the "surplus domestic product" in that year. If the data are dyad-year (leader-dyad-year), the function adds eight total columns for the first state (i.e. ccode1) and the second state (i.e. ccode2) for all these estimates. If the data are state-year (or leader-year), the function returns four additional columns to the original data that contain that same information for a given state in a given year.


Steven V. Miller


Anders, Therese, Christopher J. Fariss, and Jonathan N. Markowitz. 2020. "Bread Before Guns or Butter: Introducing Surplus Domestic Product (SDP)" International Studies Quarterly 64(2): 392–405.


# just call `library(tidyverse)` at the top of the your script

cow_ddy %>% add_sdp_gdp()

create_stateyears() %>% add_sdp_gdp()

create_stateyears(system = "gw") %>% add_sdp_gdp()

peacesciencer documentation built on March 31, 2023, 8:37 p.m.