Compiles multiple indexes -- including V-Dem, Polity, and EIU's Democracy Index -- into one interactive interface.

"Classification of political regimes as democracy and dictatorship. Classification of democracies as parliamentary, semi-presidential (mixed) and presidential. Classification of dictatorships as military, civilian and royal. Coverage: 202 countries, from 1946 or year of independence to 2008."

These researchers are collecting data on the characteristics of constitutions.

Database of constitutions from around the world.

Compiles provisions related to gender from constitutions around the world in searchable database.

Contains 125 variables primarily measuring electoral rules and the political system.

Strength of political parties by ideology in capitalist democracies.

Analyzes stability risks of 178 countries against twelve social, economic, and political risks.

Publishes Freedom in the World and Freedom of the Press, annually assessing civil liberties and media independence in 200 countries and territories.

Macro time series, micro time series, government finance, and social indicators including ethnic fractionalization, party fractionalization, regime changes, and fixed factors. 1960-99. Easterly and Yu.

Ranks 144 countries against 23 indicators ranging from military expenditure to respect for human rights.

Measures 123 countries according to measures under categories such as rule of law, openness, market characteristics, security of transactions, social characteristics.

"IAEP is a collection of data on political institutions and practices, and political elections for all countries in the international system between 1972 and 2005."

Links to the websites of world parliaments.

"The Inter-parliamentary Union PARLINE database contains information on the structure and working methods of 261 parliamentary chambers in all of the 186 countries where a national legislature exists."

Measures parties positions on European integration, ideology, and policy.

The project is based on quantitative content analyses of parties’ election programs from more than 50 countries covering all free, democratic elections since 1945.

Latin American party systems and democracy and democratization.

Measures party system fragmentation and disproportionality.

Variety of useful shared datasets covering regime types, elections, civil liberties, and much more.

Measures political and economic risk associated with a country.

Measures state-sanctioned torture, killings, disappearances, and imprisonment; yearly report (1976-2006) developed by Mark Gibney at University of North Carolina.

Measures regime characteristics (democracy/autocracy) for all states over 500,000 from 1800 to 2018. Also find other data on conflict and peace at this link.

Lists of heads of state and government of all countries and territories back to 1700.

The Corruption Perceptions Index, Bribe Payers Index, and Global Corruption Barometer assess attitudes toward and perceived levels of corruption around the world.

Varieties of Democracy (V-Dem) measures all countries, 1900-present, on these democratic qualities: Electoral, Liberal, Participatory, Majoritarian, Consensual, Deliberative, and Egalitarian. Also provides subcomponent measures re. elections, judiciary, etc.; and collects data to measure these principles. Explore the different datasets that V-Dem produces.

Offers visualizations of data drawn from Transparency International, World Bank, and others regarded political corruption of states around the world.

140+ governance datasets from the World Bank.

Aggregated governance indicators for 209 countries, 1996-2004, from the World Bank.