This dataset covers all sovereign countries (including micro-states) from 1800 to 2020. Generally, we use United Nations membership to define when micro-states enter the data set. We thank Benjamin A.T. Graham and his students at USC (Valeria Flores-Cadena, Jiaming Shi, Affan Rahman, and Apurvi Bhartia) for providing their own democracy ratings and supporting information as part of a class project.

The authors argue that their measure’s distinguishing features—a concrete, dichotomous coding and a long time span—are of critical value to empirical work on democracy. Inspired by Robert Dahl, they define a country as democratic if it satisfies conditions for both contestation and participation. Specifically, democracies feature political leaders chosen through free and fair elections and satisfy a threshold value of suffrage.