Democracy indices are quantitative and comparative assessments of the state of democracy for different countries according to various definitions of democracy.
The democracies indices differ in whether they are categorical, such as classifying countries into democracies, hybrid regimes, and autocracies, or continuous values. The qualitative nature of democracy indices enables data analytical approaches for studying causal mechanisms of regime transformation processes.
Democracy indices differ in scope and weighting of different aspects of democracy, including the breadth of core democratic institutions, competitiveness and inclusiveness of polyarchy, freedom of expression, various aspects of governance, democratic norm transgressions, co-option of opposition, electoral system manipulation, electoral fraud, and popular support of anti-democratic alternatives.
Prominent democracy indices
Operating
Bertelsmann Transformation Index by the Bertelsmann Stiftung, evaluations by country, regional, and general experts, some evaluations by representative surveys of regular citizens. Spectrum: then averaging of scores for: hard-line autocracy, moderate autocracy, very defective democracy, defective democracy, consolidating democracy. The Economist Democracy Index, by the UK-based Economist Intelligence Unit, is an assessment of countries' democracy. Countries are rated as full democracies, flawed democracies, hybrid regimes, or authoritarian regimes. The index is based on five different categories measuring pluralism, civil liberties, and political culture. Freedom in the World, is a yearly survey and report by the U.S.-based non-governmental organization Freedom House that measures the degree of civil liberties and political rights in every nation and significant related and disputed territories around the world. The Global State of Democracy Indices by International Institute for Democracy and Electoral Assistance assesses democratic performance using different types of sources: expert surveys, standards-based coding by research groups and analysts, observational data and composite measures. V-Dem Democracy indices by V-Dem Institute distinguishes between five high-level principles of democracy: electoral, liberal, participatory, deliberative, and egalitarian, and quantifies these principles. The V-Dem Democracy indices include the Citizen-initiated component of direct popular vote index, which indicates the strength of direct democracy and the presidentialism index, which indicates higher concentration of political power in the hands of one individual.
Indices measuring aspects of democracy
Effective number of parties is an index of the adjusted number of political parties in a country's party system. Fragile States Index, formerly the Failed States Index, is an annual report that aims to assess states' vulnerability to conflict or collapse, ranking all sovereign states with membership in the United Nations where there is enough data available for analysis. Gallagher index measures an electoral system's relative disproportionality between votes received and seats in a legislature.
Other measured aspects of democracy include voter turnout and political efficacy.
Historical
Democracy-Dictatorship Index is a binary measure of democracy and dictatorship. Democracy Ranking is a democracy ranking by the Association for Development and Advancement of the Democracy Award. Polity data series contains annual information on regime authority characteristics and covers the years 1800–2018 based on competitiveness, openness, and level of participation, sponsored by the Political Instability Task Force (PITF). Boix-Miller-Rosato dichotomous coding of democracy, easy-to-observe characteristics, few evaluations by own researchers based on academic literature. As a classification: non-democracy to democracy. Lexical Index of Electoral Democracy (LIED) by Skaaning et al. democracy's characteristics assessed with easy-to-observe characteristics, few evaluations by own researchers based on academic research. Then evaluating whether necessary characteristics are present or not. The Index of Democratization created by Tatu Vanhanen