Version 4 of the Militarized Interstate Dispute (MID) data collection compiled by the Correlates of War Project provides information about conflicts in which one or more states threaten, display, or use force against one or more other states between 1816 and 2010. By definition, “Militarized interstate disputes are united historical cases of conflict in which the threat, display or use of military force short of war by one member state is explicitly directed towards the government, official representatives, official forces, property, or territory of another state. Disputes are composed of incidents that range in intensity from threats to use force to actual combat short of war” (Jones et al. 1996: 163).
Version 3.10 of the MID data set covered the 1816-2001 period. The data collection project that culminated in version 4.0 gathered new data on all MIDs that began between 2002 and 2010, along with those MIDs that began before 2002 but were still ongoing on December 31, 2001. Version 4 also updates the earlier data set with corrections made after an investigation of cases where errors or discrepancies had been reported to the COW project between 2007 and 2013. The version 4 MID data should be considered to supersede other MID data sets.
In any papers or publications that utilize this data set, users are asked to give the version number and cite the article of record for the data set, as follows:
Main Bibliography Entry:
Palmer, Glenn, Vito D'Orazio, Michael Kenwick, and Matthew Lane. 2015. "The MID4 Data Set: Procedures, Coding Rules, and Description." Conflict Management and Peace Science. Forthcoming.
Dyadic Data Set Bibliography Entry:
Ghosn, Faten, and Scott Bennett. 2003. Codebook for the Dyadic Militarized Interstate Incident Data, Version 3.10. Online: http://correlatesofwar.org.
MID 3 Bibliography Entry:
Ghosn, Faten, Glenn Palmer, and Stuart Bremer. 2004. "The MID3 Data Set, 1993–2001: Procedures, Coding Rules, and Description." Conflict Management and Peace Science 21:133-154.
MID 2.1 codebook/citation: The codebook for the MID data version 3.0 builds on the documentation for the MID version 2.1 data set:
Jones, Daniel M., Stuart A. Bremer and J. David Singer. 1996 ."Militarized Interstate Disputes, 1816-1992: Rationale, Coding Rules, and Empirical Patterns." Conflict Management and Peace Science 15:163-213.
Questions and Feedback
The MID data are hosted by Glenn Palmer, Penn State, under the COW Data Set Hosting Program. In case of questions or concerns concerning the data or coding rules, he may be contacted by email at email@example.com.
MID 4 Project Development
The latest iteration of the Correlates of War Project's Militarized Interstate Dispute Data (MID 4) covers the period 2002-2010, adding to the MID data gathered for the period 1816-2001. MID 4.0 was developed largely at the Pennsylvania State University under the direction of Glenn Palmer and with the assistance of two grants from the National Science Foundation (SES-0719634 and SES-0924240). Financial and research support from the Department of Political Science at Penn State University was provided and aided the project significantly. Phil Schrodt, Scott Bennett (Penn State) and Paul Diehl (Illinois) were instrumental in the development and completion of the project. Colleagues at Rice University and the University of Alabama, directed by Richard Stoll and Doug Gibler, respectively, provided timely and valued assistance.
An article of record for the MID 4 Data is in preparation as of January, 2014. We will be announcing the specifics of that article shortly.
A re-evaluation of the MID data for the years 1816-2001 is currently (January, 2014) in progress. We anticipate that a number of disputes and incidents will be altered in some form or removed from the data completely. We will release the revised data, explaining the changes made, as soon as possible.
The files associated with the MID 4 data set can be obtained below in ZIP files. All data files are in .csv (comma-delimited) format. In this format, values are separated by commas, with string values (e.g. state names) in quotations. The first line of each data file is a header record containing the variable names. The codebooks and narratives are in .pdf format.
MID-level data and documents
There are five files in the MID-level ZIP file:
1.MID_v4.0_Codebook.pdf: Main codebook for the MID 4.0 data set, describing file formats and listing variables contained in the MIDA and MIDB data files.
2. MIDA_4.01.csv: Data on MIDs from 1816-2010, at the dispute level. Contains one record per militarized dispute.
3. MIDB_4.01.csv: Data on MIDs from 1816-2010, at the participant level. Contains one record per militarized dispute participant.
4. MID_Narratives_1993-2001.pdf: Narratives for 1993-2001 MIDs containing a brief prose summary of key actors and actions.
5. MID_Narratives_2002-2010.pdf: Narratives for 2002-2010 MIDs containing a brief prose summary of key actors and actions.
Incident-level data and documents
There are three files in the incident-level ZIP file:
1. MII_v4.0_Codebook.pdf: Main codebook for the MID 4.0 incident data sets, describing file formats and listing variables contained in the MIDI and MIDIP data files.
2. MIDI_4.01.csv: Data on incidents within MIDs from 1993-2010 (along with disputes ongoing as of 12/31/1992), at the incident level. Contains one record per militarized incident.
3. MIDIP_4.01.csv: Data on incidents within MIDs from 1993-2010 (along with disputes ongoing as of 12/31/1992), at the incident-participant level. Contains one record per participant in each incident.
Dyadic MID data and documentation (MID 3.1 only; MID 4 coming soon):
There are two files in the dyadic MID ZIP file:
1. Codebook for Dyadic MID Data v3.10.pdf: Main codebook for the dyadic version of the MID 3 data set, describing coding procedures and the dyadic file format, and listing variables.
2. MIDDyadic_3.10.csv: Data on dyadic MIDs from 1993-2001 (along with disputes ongoing as of 12/31/1992), at the dyad level. Contains one record per dyadic MID.
Documents discussing data changes:
There are four files in the data changes ZIP file:
1. MID_Changes_as_of_v4.0.pdf: Document discussing changes made to MID data between MID v3.10 and v4.0.
2. MID_v3.0.associated document.pdf: Auxiliary information presented during release of the MID 3.0 data set, including discussion of new and changed variables relative to MID 2.1, updates, and a discussion of particular case codings in MID 3.0.
3. Discussion - MID changes as of v3.10.pdf: Document discussing changes made to MID data since v3.02.
4. Discussion - MIDs reviewed and unchanged as of v3.10.pdf: Document discussing changes/questions examined, but where changes were not needed.