Archigos. A Data Base on Leaders 1875 - 2004. A collaborative effort with Kristian Skrede Gleditsch (University of Essex, UK) and Giacomo Chiozza (Vanderbilt).

• Version 2.8.1 (February 2008) -- which has the leader-spell as the unit of observation -- contains information on the date and manner of entry and exit of over 3,000 leaders 1875 - 2004 as well as their gender, birth- and death-date, previous times in office and their post-exit fate. For ease of use, we also provide a version of these data with time-varying records, where the unit of observation is the leader-year. (This is an update, the previous version mistakenly coded leaders in office 31 December 2004 as failing.) Both data sets are in Stata format. The full data contains detailed information on how leaders lost office. We withhold the exit variables because they are central to Chiozza and Goemans' book manuscript Leaders and International Conflict. Upon request, we will make this information available in individual cases.
• To introduce the data to the wider community we wrote "Introducing Archigos: A Data Set of Political Leaders," (forthcoming in the Journal of Peace Research, 46(2), March 2009) . This article describes some very basic but nonetheless interesting patterns. We would appreciate it if users would cite this article as their reference for the data. A codebook with case descriptions--about 600 pages--is available. This codebook and information is continuously updated.
• I completed collecting data on election dates for leaders in Archigos for the period 1919 - 2006 (in cvs format). The file contains data for the earlier period 1900 - 1918 but I do not claim this is comprehensive or complete. This data is not yet integrated in Archigos. I would appreciate feedback on omissions, mistakes and addenda.
• We will continue to update and extend Archigos. Future versions will include a new variable which records whether a leader was related to a previous leader. In addition, future versions will offer finer-grained codings on how leaders entered and left office, as well as information on term limits.