Part 3: User’s guide

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Datasets and recommended reading

Democracies differ greatly across the world’s regions. To be able to properly assess how well – or how badly – democracy works in a given country it is necessary to use quantitative data to ‘measure’ the various aspects of a democracy. Measuring democracy pursues two aims. The first is to establish if a regime is a democracy or not; the second aim is to determine the degree of democracy, a task that requires analysing to what extent a country meets standards defining democracy, such as, the rule of law, accountability, responsiveness, freedom as well as equality and solidarity.

Besides the empirical approach the study of democracy also benefits from a comparative approach. Alexis de Tocqueville (1805-1859), who was a French sociologist, historian and political theorist, can be called the first comparativist. He travelled to the United States to observe American democracy and has taught us that the only way we can fully understand our own political system is by comparing it to others. When we compare our own experience with that of other countries we not only understand better our own politics, but can also see a wider range of alternatives and discover the virtues or shortcomings of our own political life.

Having now started thinking about how we connect reality to research, the next question is where to find data. Data partners play an important role, and we have partnered with the leading ones.


Varieties of Democracy (V-Dem), one of data partners, provides general data on the quality of democracy. Data and reading on specific topics are included below.

A very useful introductory text for a range of different political institutions can be found in the latest edition of Comparative Politics, Daniele Caramani, editor. The book provides not only concise overviews of single institutions, but also helpful online resources.

The Poliscidata website serves as a good starting point for discovering any number of databases not only about political institutions, but also about specific geographic regions of the world, including African politics.

A number of datasets have attempted to encompass the full array of political institutions that are at work in contemporary democracies in order to study the variety of institutions as well as their interactive effects. These endeavours include the Comparative Political Data Set, and the Database of Political Institutions.

Democratic regimes

Robert Elgie has attempted to classify the current state of around 180 countries in the world according to the three types of democratic regimes: parliamentarism, semi-presidentialism and presidentialism. These data can be found on two separate web pages, here and here. Other datasets, like the Database of Political Institutions, provide more limited categorizations, distinguishing simply between parliamentary and presidential regimes.


A major database of parliamentary rules and procedures can be found through the Parline webpage of the International Parliamentary Union. Most of the time, these data are textual, meaning they describe rules, rather than coding them with numbers. (See also the archived version.)  However, as a reference site it is helpful to compare countries and the workings of their legislatures.

Major analytical works of parliamentary procedure include Patterns of parliamentary behavior: passage of legislation across Western Europe, by Döring and Hallerberg (2004), and before that the magisterial volume Parliaments and Majority Rule in Europe, edited by Döring (1995).

Coalition governments

The ParlGov (Parliaments and Governments) database provides a very comprehensive dataset of all cabinets and political parties for 37 advanced democracies stretching back all the way to 1900. It does not classify the cabinets directly into coalition type, but it does show the parties involved and their seat shares. A similar dataset is provided by the Party Systems and Governments Observatory.

Information on coalition governance mechanisms has not yet been fully systematized into an easily accessible database. However, some datasets have emerged from a series of international projects spearheaded by Wolfgang Müller, Kaare Strøm, and Torbjörn Bergman. These can be found on the website of the European Representative Democracy Data Archive. The numerous edited volumes that have emerged from these projects are also key reference works in the field.


Robert Elgie has put together two indices of presidential power based on different aggregations of other existing datasets. These can be found under the Presidential Power Scores section of his presidentialism website.

A comparative database on presidential impeachment rules has not yet been compiled, but many comparative works exist, such as Checking executive power: Presidential impeachment in comparative perspective, edited by Baumgartner and Kada (2003).

Political parties

The ParlGov database has a sub-set of data on political parties, including a classification of their ideological families. This can be used to see, which ideological cleavages have dominated in what countries during which periods of time.

Political party manifestos have also been a huge area of comparative research. The Manifesto Project has been the leader in this field, providing an extensive historical database of electoral manifestos coded according to policy areas and going back far into the 20th century. The database website also includes a visualization tool that allows students to generate graphs for presentations and research papers.

The Political Party Database Project attempts to provide comparative information on party resources and organization in advanced democracies starting from 2002. The database is useful because it attempts to code more systematically the inner workings of political parties.

The Party Systems and Governments Observatory is the most extensive database that looks at a range of indicators for party systems (electoral volatility, fragmentation, number of new parties, polarization, electoral disproportionality).

The International Institute for Democracy and Electoral Assistance (IDEA) has one of the leading databases for the comparative study of party finance and its oversight bodies. It also has databases on voter turnout, direct democracy, as well as its own Global State of Democracy Index. 

Electoral systems

The most authoritative source for information on electoral systems comes from the Comparative Study of Electoral Systems, which not only provides background information on electoral rules, but also organizes key post-electoral surveys that study the effects of these rules on the behavior of voters and politicians.

The Parline database also provides an overview of electoral systems around the world, as does the International IDEA.

Constitutional Courts

The Comparative Constitutions Project provides extensive information on the structure of constitutions around the world. It also provides useful variables for comparing the judicial oversight mechanisms of constitutional courts. The Venice Commission of the Council of Europe focuses more specifically on the constitutional courts of advanced democracies.

For qualitative research the Human Relations Area Files at Yale University provide rich sources of ethnographic information:; more specific historical accounts have to be searched on a country-by-country basis. 

Quantitative survey research has improved considerably over the last few decades.

Major sources are the regional barometers (Afrobarometer, Arab Barometer, Asian Barometer, Eurasian Barometer, Latinobarometro), now organized jointly in the framework of Global Barometer Surveys (, the Eurobarometer (, and the European Social Survey ( On a worldwide basis, the various waves of the World Values Surveys ( have now reached a fairly high coverage. All these surveys provide rich information on a large variety of political cultural aspects, often related to processes of democratization, but also of recent populist or authoritarian tendencies.

More specific aspects concerning the quality of governance, perception of corruption or electoral integrity can be found in the following sources:

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