An Analysis of the Militarized Interstate Dispute (MID) Dataset, 1816–2001

This research note discusses a five-year examination of the original coding work of the Militarized Interstate Dispute (MID) project. After strictly applying MID coding rules, we recommend dropping 251 cases (or over 10% of the dataset), as either we were unable to find a militarized incident in the historical record or the dispute appeared elsewhere in the data. We found evidence linking 75 disputes to other cases, and we could not identify 19 cases in the historical record. Among the remaining disputes, we recommend major changes (changes in dispute year, fatality level, and participants) in 234 disputes and minor changes in 1,009 disputes. We use this article to examine the potential impact of our suggestions on existing studies. Though we identified several systematic problems with the original coding effort, we also find that these problems do not affect current understandings of what predicts the onset of interstate conflict. However, estimates in our replications of three recent studies of dispute escalation, dispute duration, and dispute reciprocation all witness substantial changes when using corrected data—to the point of reversing previous conclusions in some cases.