Primary source for public opinion on elections, political participation, characteristics of voters, and for whom they voted, 1948-2008. It also provides summary data on social, economic, partisanship, and public opinion, 1948 to present.

The CCES is a 30,000+ person national stratified sample survey administered by YouGov Polimetrix. Half of the questionnaire consists of Common Content asked of all 30,000+ people, and half of the questionnaire consists of Team Content designed by each individual participating team and asked of a subset of 1,000 people.

An open source web application to share, preserve, cite, explore, and analyze research data.

From the International Institute for Democracy and Electoral Assistance (IDEA), depicts democratic trends at the country, regional and global levels across a broad range of different attributes of democracy from 1975–2017.
The indices present data for 158 countries around the world and consist of 5 main democracy attributes and 16 subattribute scores per country per year.

The Polity conceptual scheme is unique in that it examines concomitant qualities of democratic and autocratic authority in governing institutions, rather than discreet and mutually exclusive forms of governance. This perspective envisions a spectrum of governing authority that spans from fully institutionalized autocracies through mixed, or incoherent, authority regimes (termed "anocracies") to fully institutionalized democracies. Scroll down the page to find the data downloads.

Varieties of Democracy (V-Dem) is a new approach to conceptualizing and measuring democracy. We provide a multidimensional and disaggregated dataset that reflects the complexity of the concept of democracy as a system of rule that goes beyond the simple presence of elections. The V-Dem project distinguishes between seven high-level principles of democracy: electoral, liberal, participatory, deliberative, egalitarian, majoritarian and consensual, and collects data to measure these principles.

Survey of 100 countries gathering information on economic development, democratization, religion, gender, well-being, and other topics. Coverage 1981-2014.