Kristian Skrede Gleditsch


  Download: The list of independent states as a tab delimited text file.
  Download: A tentative list of microstates that fall short of the 250,000 threshold.

This is version 7.0 of the list of independent states, updated through 31 December 2020, posted on 13 May 2021 (old versions iisystem.dat and microstatessystem.dat).


  Utilities: These Perl scipts can be used to generate annual observations according to various specifications from the core data:

  • Program to generate annualized data on states is available here
  • Program to generate dyad years is available here

  Documentation: These data are explained in greater detail in Gleditsch, Kristian S. & Michael D. Ward. 1999. "Interstate System Membership: A Revised List of the Independent States since 1816." International Interactions 25: 393-413. Users should also consult the accompanying case description document outlining the classification of states (in PDF format). Note that the current version of the data contain some changes over the table in the Gleditsch and Ward 1999 article. These are documented in the case description file.

  Note on opening the data: A large file (e.g., all dyads in the world) is typically too large to be opened in Microsoft Excel. I recommend using a plain ascii editor, for example, the Programmer's File Editor available here.


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