README for ksgp4duse.asc and ksgp4use.asc --------------------------------------------------------------- Kristian Skrede Gleditsch Department of Government University of Essex Colchester CO7 9QF, UK email: ksg@essex.ac.uk First version, 1.0: 13 October 2003 Second version, 2.0: 22 January 2007 (updated to 2004) Second version, 2.1: 17 May 2007 (fixed duplicate entry for Italy/Sardinia in 1961 in annual data) Third version, 3.0: 7 October 2008 Updated through 2008 Fourth version, 3.1: 8 December 2008 Fixed duplicate entries for YUG 2006 due to separate entries for Serbia with and w/o Montenegro in 2006 in the Polity IV annual data This file modified: 8 December 2008 (minor revision to ksgp4use.asc) The Polity data are not based on an explicit list of the universe or population of units. For example, the Polity data lack information about the characteristics of various independent states for certain time periods (for example, Switzerland 1816-1848) and also include observations for Polities that are not independent states (e.g., Norway before independence in 1905) These files provide two alternate versions of the P4 and P4D data to make it easier to use these data in analyses where the universe is the population of independent states. These files conform with the population in the Gleditsch and Ward list of independent states (see http://privatewww.essex.ac.uk/~ksg/statelist.html). These data modify various unit labels and dates in the Polity data, following the standards in the Gleditsch and Ward list. These files also contain estimates of the polity scores of states not in the original Polity data. Note that although these data are based on the Polity data they differ substantially in the population or units of observations. They also contain extrapolations and estimates not included in the original Polity data. They are provided to facilitate use of the data for research purposes different from those envisioned by the Polity project. However, these modified versions of the data are not endorsed by the Polity project in any way The modified files are ksgp4use.asc data in annualized format ksgp4duse.asc data in 3d format, i.e., one line per state/polity observation If you wish to refer to these data specifically, please use the following citation: Gleditsch, Kristian Skrede. 2008. Modified Polity P4 and P4D Data, Version 3.0., URL: http://weber.ucsd.edu/~kgledits/Polity.html. Summary of main changes (relative to the regular Polity data) ------------------------------------ I. ID codes * 200 UKG United Kingdom The UKG acronym is used in the G&W list * 260 FRG Federal Republic of Germany Whereas the Polity project uses the 255 GMY code for Germany after unification, the G&W list considers Germany after unification a continuation of 260 FRG (Federal Republic of Germany) * 300 AUH/305 AUS Austria/Austria Hungary The dual monarchy of Austria and Hungary is coded as 300 AUH prior to 14/11/1918. * 325 ITA Italy/Sardinia 325 ITA is used for Italy and Sardina. Whereas the Polity project considers these different units, the G&W list treats unifed Italy under King Victor Victor Emmanuel II as a continuation of Sardina, as the other Italian states are annexed to an existing Polity. * 340 SER/345 YUG Serbia/Yugoslavia Data for assigned for 340 SER (Serbia) in the period 01/12/1918 to 31/12/2002 in the Polity project are classified as 345 YUG (Yugoslavia) in the modified data, Serbia become part of the Kingdom of the Serbs, Croats, and Slovenes on 1 December 1918. The 347 YGS code is not used in the modified data. * 365 RUS Russia/Soviet Union/Russia The G&W list treats the Soviet Union as a continuation of Russia, and Russia as a continuation of the Soviet Union. The label 364 USR is not used. * 678 YEM Yemen/Yemen Arab Republic The G&W list considers Yemen after unification a continuation of North Yemen. South Yemen is defeated by North Yemen after they try to seceede from the union. The code 678 YEM is used both for Yemen and the Arab Republic. The codes 679 and YEM are not used * Special polity ID codes The codes 529 ETI, 769 PKS, and 818 VIE are not used in the modified data. * Observations for 212 LUX Luxembourg and 395 ICE Iceland are taken from the Polity 98D data. These were dropped from Polity 4 as total population is less than 1 million. These states are above the Gleditsch and Ward threshold of 250,000 inhabitants. * Polity scores for countries not in the Polity data are estimated from the Freedom House data, using on a linear prediction based on the Political Rights and Civil Liberties components. The vector of predicted polity scores has a 0.8798 correlation with the vector of observed polity scores. (Other functional forms such as taking the log one or all of the variables did not improve the fit of the prediction.) * The origin codes for each observation listed below. Table of origin code values ----------------------------------------------------------------- ksgp4use.asc ---------------------------------- 0: Observation from Polity 4 data 1: Observation from old Polity data (98d) 2: Polity score estimated from Freedom House data 3: Extrapolated polity score 4: Guesstimated polity score ksgp4duse.asc ---------------------------------- 0 Observation and date from Polity 4D data -1: Observation and date from old Polity data (98d) 1: Observation from Polity data, truncated start date 2: Observation from Polity data, truncated end date 3: Observation from Polity data, truncated start and end date 4: Extrapolated start date 5: Extrapolated end date 6: Extrapolated start and end date 7: Polity score estimated from Freedom House data 8: Guesstimated polity score