The ‘Varieties of Democracy’ data: how do researchers measure democracy?

Measuring the state of democracy across the world helps us understand the extent to which people have political rights and freedoms.

But measuring democracy comes with many challenges. People do not always agree on what characteristics define a democracy. These characteristics — such as whether an election was free and fair — are difficult to define and assess. The judgment of experts is to some degree subjective. They may disagree about a specific characteristic or how something as complex as a political system can be reduced into a single measure.

How do researchers address these challenges and measure democracy?

What is the Varieties of Democracy (V-Dem) project?

In some of our work on democracy, we rely on data published by the Varieties of Democracy (V-Dem) project.1

The project is managed by the V-Dem Institute, based at the University of Gothenburg in Sweden. It spans seven more regional centers around the world and is run by five principal investigators, dozens of project and regional managers, and more than 100 country coordinators.

V-Dem is funded through grants and donations by government agencies and private foundations, such as the Swedish Research Council, the European Commission, and the Marcus and Marianne Wallenberg Foundation.

How does V-Dem characterize democracy?

True to its name, the Varieties of Democracy project acknowledges that democracy can be characterized differently, and measures electoral, liberal, participatory, deliberative, and egalitarian characterizations of democracy.

At Our World in Data we primarily use V-Dem’s Electoral Democracy Index to measure democracy.2 The index is used in all of V-Dem’s other democracy indices because V-Dem considers there to be no democracy without elections. The other aspects can therefore be thought of as measuring the quality of a democracy.

V-Dem characterizes electoral democracy as a political system in which political leaders are elected under comprehensive voting rights in free and fair elections, and freedoms of association and expression are guaranteed. More specifically, this means:

  • Elected political leaders: broad elections choose the chief executive and legislature
  • Comprehensive voting rights: all adult citizens have the legal right to vote in national elections
  • Free and fair elections: no election violence, government intimidation, fraud, large irregularities, and vote buying
  • Freedom of association: parties and civil society organizations can form and operate freely
  • Freedom of expression: people can voice their views and the media can present different political perspectives

You can find data on the other democracy indices, electoral democracy’s characteristics, and other derived measures in our Democracy Data Explorer.

How is democracy scored?

The Electoral Democracy Index scores each country on a spectrum, with some countries being more democratic than others.

The spectrum ranges from 0 (‘highly undemocratic’) to 1 (‘highly democratic’).

This scoring thereby differs from other approaches such as ‘Regimes of the World’ and other projects, which classify countries as a binary: either they are a democracy or not.

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What years and countries are covered?

As of version 13 of the dataset, V-Dem covers 202 countries, going back in time as far as 1789. Many countries have been covered since 1900, including before they became independent from their colonial powers.

How is democracy measured?

How does V-Dem work to make its assessments valid?

To actually measure what it wants to capture, V-Dem assesses the characteristics of democracy mostly through evaluations by experts.3

These anonymous experts are primarily academics and members of the media and civil society. They are also often nationals or residents of the country they assess, and therefore know its political system well and can evaluate aspects that are difficult to observe.

V-Dem’s own team of researchers supplements the expert evaluations. They code some easier-to-observe rules and laws of the political system, such as whether the legislature has a lower and upper house.

How does V-Dem work to make its assessments precise and reliable?

V-Dem uses several experts per country, year, and topic, to make its assessments less subjective. In total, around 3,500 country-experts fill surveys for V-Dem every year.

While there are fewer experts for small countries and for the time before 1900, they rely typically on 25 experts per country and 5 experts per topic.

How does V-Dem work to make its assessments comparable?

V-Dem also works to make their coders’ assessments comparable across countries and time.

The surveys ask the experts to answer very specific questions on completely explained scales about sub-characteristics of political systems — such as the presence or absence of election fraud — instead of making them rely on their broad impressions.

The surveys are available in English, Arabic, French, Portuguese, Russian, and Spanish to reduce misunderstandings.

Experts further evaluate hypothetical countries, many coded several countries, and they denote their own uncertainty and personal demographic information.

V-Dem then uses this information to investigate expert biases, which they have found to be limited: they only find that experts from a country tend to be stricter in their assessments. 4

How are the remaining differences in the data dealt with?

V-Dem uses a statistical model to address any remaining differences between coders.5

The model combines the experts’ ratings of actual countries and hypothetical countries, as well as the experts’ stated uncertainties and personal demographics to produce best, upper-, and lower-bound estimates of many characteristics.6

V-Dem provides these different estimates for all of its main and supplementary indices, including the Electoral Democracy Index and the subindices for free and fair elections, freedom of association, and freedom of expression.

With the different estimates, V-Dem explicitly acknowledges that its coders can be uncertain or make errors in their measurement.

The overall Electoral Democracy Index score is the result of weighing, multiplying, and adding up the subindices.7

The subindices are weighted because V-Dem considers some of them as more important than others: elected officials and voting rights are weighted less because they capture more formal requirements, as opposed to free and fair elections and the freedoms of association and expression that rely more on expert assessments.

The subindices are partially multiplied and partially added up because V-Dem wants the subindices to partially compensate for one another, and partially for them to reinforce each other. An example of compensation is voting rights partially making up for a lack of rights to assemble and protest, whereas an example of reinforcement is voting rights mattering more if voters can also choose opposition candidates.

How is the data made accessible and transparent?

V-Dem releases its data publicly, and makes it straightforward to download and use.

It publishes the overall scores, the underlying subindices, and several hundred specific questions by country-year, country-date, and coder.

V-Dem also releases detailed descriptions of how they characterize democracy, the questions and coding procedures that guide the experts and researchers, as well as why it weighs, adds, and multiplies the scores for specific characteristics.

How do we change the data?

In our work, we expand the years covered by V-Dem further.

To expand the time coverage of today’s countries and include more of the period when they were still non-sovereign territories, we identified the historical entity they were a part of and used that regime’s data whenever available.8

We also calculated regional and global averages of the Electoral Democracy Index and its sub-indices, weighted and unweighted by population.

Our code and data are available on GitHub and record our revisions in detail.

How often and when is the data updated?

V-Dem releases a new version of the data each year in March.

We at Our World in Data aim to update our own data within a few weeks of the release.

What are the data’s shortcomings?

There are shortcomings in the way the Electoral Democracy Index characterizes and measures democracy.9

The index focuses on an electoral understanding of democracy and does not account for other characterizations, such as democracies as egalitarian political systems, in which political power is equally distributed to allow everyone to participate. This means that some of the most economically-unequal countries in the world, such as Brazil and South Africa, are classified as broadly democratic in recent years.10

V-Dem also does not cover some countries with very small populations.

Furthermore, the index is more difficult to interpret than other measures. Measures that group countries into democracies and autocracies, such as the Regimes of the World classification, make it possible to say which country was a democracy.

The Electoral Democracy Index makes no clear assessment there, and only allows us to say whether a country is relatively democratic by comparing it to the range of the index, to other countries, or to the same country at another point in time. And when doing so, it is still difficult to say how large these differences are.11

The assessment of the Electoral Democracy Index remains to some extent subjective. Its index is built on difficult evaluations by experts that rely less on easier-to-observe characteristics, such as whether regular elections are held.

Finally, the index’s aggregation remains to some extent arbitrary. It is unclear why these specific subindices were chosen; and why two subindices, elected officials and voting rights, are weighted less than the others.

What are the data’s strengths?

Despite these shortcomings, the index tells us a lot about how democratic the world was in the past and today.

Its characterization of democracy as an electoral political system, in which citizens get to participate in free and fair elections, is commonly recognized as the basic principle of democracy and shared by all of the leading approaches of measuring democracy

Because it treats democracy as a spectrum, the index is able to capture both big and small differences in the political systems of countries, and to record small changes within countries over time. This allows us to observe whether one country is more democratic than another, or whether a country has become more or less democratic over time.

The index also covers many countries and years. With the exception of microstates, it covers all countries in the world. Many countries are covered since 1900 — even while they were colonized by another country — and some of them as far back as 1789.

Finally, V-Dem takes many steps to make its assessments valid, precise, comparable across countries and time, and transparent. It relies on many country and subject experts answering detailed surveys to measure aspects of political systems that are often difficult to observe and acknowledges the remaining uncertainty in their assessments.

What is our summary assessment?

Whether V-Dem’s Electoral Democracy Index is a useful measure of democracy will depend on the questions we want to answer.

The index will not give us a satisfying answer if we are interested in non-electoral understandings of democracy (or different understandings of electoral democracy); if we are also interested in the political systems of microstates; and only interested in big differences in the political systems of countries.

In these cases, we will have to rely on other measures.

But if we value a sophisticated measure based on the knowledge of many country experts and are interested in big and small differences in electoral democracy, within and across countries, and far into the past, we can learn a lot from this data.

It is for these latter purposes we use the measure in some of our reporting on democracy.

Keep reading on Our World in Data


I thank Edouard Mathieu, Hannah Ritchie, and Max Roser for their very helpful comments and ideas about how to improve this article.