Sovereign state

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What you should know about this indicator

  • For the years until 1919, Correlates of War considers a country a sovereign state if it has a population of at least 500,000 people, and is diplomatically recognized by France and the United Kingdom.
  • For the years after 1919, a country is considered a sovereign state if it either at any point was a member of the League of Nations or the United Nations, or had a population of at least 500,000 people and was diplomatically recognized by at least two major powers.
Sovereign state
The country is identified as a sovereign state by Correlates of War - State System Membership dataset.
Correlates of War - State System Membership (2017) – with minor processing by Our World in Data
Last updated
September 29, 2023
Next expected update
September 2028
Date range

Sources and processing

This data is based on the following sources

This data set contains the list of states in the international system as updated and distributed by the Correlates of War Project. These data sets identify states, their standard Correlates of War “country code” or state number (used throughout the Correlates of War project data sets), state abbreviations, and dates of membership as states and major powers in the international system. Version 2016 extends the temporal domain of the collection through December 2016.

The Correlates of War project includes a state in the international system from 1816-2016 for the following criteria. Prior to 1920, the entity must have had a population greater than 500,000 and have had diplomatic missions at or above the rank of charge d’affaires with Britain and France. After 1920, the entity must be a member of the League of Nations or the United Nations, or have a population greater than 500,000 and receive diplomatic missions from two major powers.

Find more information in their codebook

Retrieved on
September 22, 2023
This is the citation of the original data obtained from the source, prior to any processing or adaptation by Our World in Data. To cite data downloaded from this page, please use the suggested citation given in Reuse This Work below.
Correlates of War Project. 2017. “State System Membership List, v2016.” Online,

How we process data at Our World in Data

All data and visualizations on Our World in Data rely on data sourced from one or several original data providers. Preparing this original data involves several processing steps. Depending on the data, this can include standardizing country names and world region definitions, converting units, calculating derived indicators such as per capita measures, as well as adding or adapting metadata such as the name or the description given to an indicator.

At the link below you can find a detailed description of the structure of our data pipeline, including links to all the code used to prepare data across Our World in Data.

Read about our data pipeline
Notes on our processing step for this indicator

We use the state system membership from Correlates of War. We assign each country to a region based on the mapping (using COW codes):

  • Americas: 2-165
  • Europe: 200-399
  • Africa: 402-626
  • Middle East: 630-698
  • Asia and Oceania: 700-999

Reuse this work

  • All data produced by third-party providers and made available by Our World in Data are subject to the license terms from the original providers. Our work would not be possible without the data providers we rely on, so we ask you to always cite them appropriately (see below). This is crucial to allow data providers to continue doing their work, enhancing, maintaining and updating valuable data.
  • All data, visualizations, and code produced by Our World in Data are completely open access under the Creative Commons BY license. You have the permission to use, distribute, and reproduce these in any medium, provided the source and authors are credited.


How to cite this page

To cite this page overall, including any descriptions, FAQs or explanations of the data authored by Our World in Data, please use the following citation:

“Data Page: Sovereign state”, part of the following publication: Bastian Herre, Pablo Arriagada and Max Roser (2023) - “State Capacity”. Data adapted from Correlates of War. Retrieved from [online resource]
How to cite this data

In-line citationIf you have limited space (e.g. in data visualizations), you can use this abbreviated in-line citation:

Correlates of War - State System Membership (2017) – with minor processing by Our World in Data

Full citation

Correlates of War - State System Membership (2017) – with minor processing by Our World in Data. “Sovereign state” [dataset]. Correlates of War, “State System Membership v2016” [original data]. Retrieved July 21, 2024 from