The V-Dem Dataset

The V-Dem Dataset is publicly available and published under a Creative Commons Attribution-ShareAlike (CC BY-SA) 4.0 license. This means that anyone is free to use, adapt, and share the data, including for commercial purposes, provided that appropriate attribution is given and that any derivative products are distributed under the same license terms.

The proper citation for the v16 dataset is:

Coppedge, Michael, John Gerring, Carl Henrik Knutsen, Staffan I. Lindberg, Jan Teorell, David Altman, Fabio Angiolillo, Michael Bernhard, Agnes Cornell, M. Steven Fish, Linnea Fox, Lisa Gastaldi, Haakon Gjerløw, Adam Glynn, Ana Good God, Allen Hicken, Katrin Kinzelbach, Joshua Krusell, Kyle L. Marquardt, Kelly McMann, Valeriya Mechkova, Juraj Medzihorsky, Anja Neundorf, Pamela Paxton, Daniel Pemstein, Josefine Pernes, Johannes von Römer, Brigitte Seim, Rachel Sigman, Svend-Erik Skaaning, Jeffrey Staton, Aksel Sundström, Marcus Tannenberg, Eitan Tzelgov, Yi-ting Wang, Tore Wig, Steven Wilson and Daniel Ziblatt. 2026. ”V-Dem [Country-Year/Country-Date] Dataset v16” Varieties of Democracy (V-Dem) Project. https://doi.org/10.23696/vdemds26.

No. Comparing absolute index values between different versions of our datasets can be misleading, due to several different factors;

1. Coders add data with every annual update.
2. We currently allow our coders to update and change their ratings back in time if they have come across new and more accurate information. This should lead to a continuous improvement of the data quality over time.
3. There is some attrition of coders as well as recruitment of additional coders for every new release.
4. We strive for full coverage and therefore continuously add new countries and expand our time-series.

For each variable the input of our Bayesian Item Response Theory Measurement model contains the coder scores for that specific question across all countries and years (in reduced form, capturing changes only). Because of all the factors mentioned above the input per variable changes with every annual release. Consequently, the output of the statistical model varies accordingly, and the scores are hence expected to change with new releases.

Each index is an aggregation of several variables. However, an interpretation of index scores is only meaningful in comparison to other index scores across time or countries within the same index (e.g. rank orders).

Our experts give their ratings on an ordinal scale; the output from applying our measurement model to these ratings is on an interval scale. Hence, the ratings as such take on discrete values but the latent scores can be of any numeric value (often between -4 and 4).

Some versions of the dataset include less variables than others, which could potentially explain why a specific variable is not included in the dataset that has been downloaded. As a first step, we would therefore recommend you to download the Country-Year Full + Others version of the data set and try again.