Varieties of Democracy (V-Dem)
A project collecting global data about democracy. Distinguishes among 7 high-level Principles of Democracy: Electoral, Liberal, Participatory, Majoritarian, Consensual, Deliberative, and Egalitarian.
Disaggregates into dozens of lower-level Components of Democracy such as regular elections, judicial independence, direct democracy, and gender equality, and provides disaggregated indicators for each conception and each component.
Covers all countries (and some dependent territories) from 1900 to the present, whenever possible and provides an estimate of measurement reliability for each rating.
All ratings are public, free of charge.