Comparative Political Data Sets

Research project

The Comparative Political Data Sets (CPDS for short) are three separate datasets compiled by researchers at the University of Berne. The three datasets contain a collection of political and institutional data, but cover different countries and time periods. The dataset called CPDS I (Armingeon et al. 2011) covers the OECD countries for the period 1960-2009 and was assembled as part of the research projects Die Handlungsspielräume des Nationalstaates and Critical Junctures: An International Comparison. The second dataset, CPDS II (Armingeon and Careja 2008), covers 28 post-communist countries for the 1989-2008 period, and was compiled as part of the research project Forms of Government: A Comparative Data Set for 28 Eastern Countries. The third dataset, CPDS III (Armingeon et al. 2011), covers 35 OECD and/or EU member countries for the 1990-2006 period. The data in this dataset are mainly drawn from the other two, but it differs from them in some respects.


  1. Comparative Political Data Set I
  2. Comparative Political Data Set II
  3. Comparative Political Data Set III

Comparative Political Data Set II


Comparative Political Data Sets


Excel, SPSS




28 countries

Last reviewed


Data types and sources

Political variables based on expert coding and election data. Socio-economic data based on official registers, national accounts and surveys, compiled from international statistical organisations.

Data download

Comparative Political Data Set II


The core of the dataset is composed of variables related to the political system and electoral rules. In addition, the dataset contains some socio-economic variables. The dataset covers many of the same topics as CPDS I, and a number of the variables are identical. However, in some cases variables measuring the same concept are operationalised differently in the two datasets, and some variables are included only in one of them. The variables in CPDS II are organised in eight thematic groups:

  1. Elections. Legislative: date of election, voter turnout, number of seats contested, electoral threshold, share of votes, share of seats. Presidential: mode of electing, term in office, date of elections, voter turnout, share of votes.
  2. Institutions. Variables such as bicameral/unicameral parliament, federalism, electoral system, referenda.
  3. Women in parliament. Percentage and number.
  4. Party system. Laakso-Taagepera and Rae indices.
  5. Complexion of government. Various government parties’ share of parliamentary support.
  6. Democracy. Year of independence or end of communist rule, various Freedom House variables, Transparency International’s CPI, violent conflict.
  7. Labour relations. Workers involved in labour disputes, working days lost due to labour disputes, unemployment rate.
  8. Economy. No data.

Geographical coverage

The dataset covers 28 post-communist countries.

Time coverage and updates

The dataset provides annual data from 1989 to 2008. Last update: September 4, 2008.


The dataset is described in the codebook, which is available for download from the website. Many of the variables are described in detail, but in some cases users must refer to other publications to find out how variables are coded.

Access conditions and cost

Available free of charge.

Access procedures

Predefined tables. The dataset is organised in separate thematic files.

Data formats

Excel, SPSS

Comparability and data quality

The data quality appears to be generally good, though there are some instances of inaccurate data or debatable coding practices (see chapter 5 in Rydland et al. (2008). Another problem concerns the categories of some variables. In some cases, the categories are not mutually exclusive, leading to countries being coded in a rather peculiar and seemingly haphazard way. This problem stems mainly from the practice of including “communist constitution or undemocratic rule” as a separate category on most variables. On the presidentialism variable, for example, both Belarus and Azerbaijan are coded as “communist or undemocratic” during the first years following independence, and then, from the mid-1990s onwards, as semi-presidential and presidential, respectively. Yet both countries have remained undemocratic since independence, and the coding of the variable therefore seems somewhat arbitrary.


Armingeon, Klaus, and Romana Careja. 2008. Comparative Data Set for 28 Post-Communist Countries, 1989-2006. Institute of Political Science, University of Berne.

Armingeon, Klaus, Romana Careja, Panajotis Potolidis, Marlène Gerber and Philipp Leimgruber. 2011. Comparative Political Data Set III 1990-2009. Institute of Political Science, University of Berne.

Armingeon, Klaus, Marlène Gerber, Philipp Leimgruber and Michelle Beyeler. 2011. Comparative Political Data Set 1960-2009. Institute of Political Science, University of Berne.

Huber, Evelyne, Charles Ragin, John D. Stephens, David Brady and Jason Beckfield. 2004. Comparative Welfare States Data Set, Northwestern University, University of North Carolina, Duke University and Indiana University.

Lijphart, Arend. 1999. Patterns of Democracy: Government Forms and Performance in Thirty-Six Countries. New Haven and London: Yale University Press.

Rydland, Lars Tore, Sveinung Arnesen and Åse Gilje Østensen. 2008. Contextual data for the European Social Survey. An Overview and assessment of extant resources. NSD Report No.124, Norwegian Social Science Data Services (NSD).