Comparative Study of Electoral Systems

Research project

Comparative Study of Electoral Systems (CSES) is a collaborative program of research among election study teams from around the world. Participating countries include a common module of survey questions in their post-election studies. The resulting data are deposited along with voting, demographic, district and macro variables. The studies are then merged into a single public dataset for use in comparative study and cross-level analysis.


Comparative Study of Electoral Systems

Comparative Study of Electoral Systems


Comparative Study of Electoral Systems






50+ countries

Last reviewed


Data types and sources

Public opinion surveys, official registers, national accounts and expert evaluations. The research agenda, the survey instrument, and the study design are developed by the CSES Planning Committee, whose members include scholars of electoral politics from around the world. This design is then implemented in each country by a selection of experts on social science, as part of their national post-election studies.

Data download

Comparative Study of Electoral Systems


The CSES is composed of three parts: first, a common module of public opinion survey questions is included in each participant country's post-election study. These "micro" level data include vote choice, candidate and party evaluations, current and retrospective economic evaluations, evaluation of the electoral system itself, in addition to standardized sociodemographic measures. Second, district level data are reported for each respondent, including electoral returns, turnout, and the number of candidates. Finally, system or "macro" level data report aggregate electoral returns, electoral rules and formulas, and regime characteristics.

Geographical coverage

The project currently covers over fifty consolidated and emerging democracies.

Time coverage and updates

1996-2011. The project is divided in to three modules, covering different time periods:

  • CSES Module 1: 1996-2001
  • CSES Module 2: 2001-2006
  • CSES Module 3: 2006-2011

Module 3 is currently published as an 'Advance Release' (a preliminary version of the dataset) and lacks some of the checking, cleaning, processing, documentation, data, and variables that are usual to the Full Release of a dataset.


The different modules are thoroughly documented in downloadable text-files, for all levels of data (micro, district and macro). In addition the site provides downloadable Macro Reports for each individual country within each module and full variable list in html/pdf-format.

Access conditions and cost

Available free of charge. Registration required.

Access procedures

Merged micro-district-macro file for each module is downloadable (ZIP) as a descriptor/syntax file that can be read into SPSS and SAS. The file also contains full documenation (TXT).

Data formats


Comparability and data quality

Although the project has a centralized infrastructure, through the planning committee and research meetings of the collaborators, which devote extensive effort to agree on the administration and submission of data, the collaborators are independent, autonomous national election studies and the details of their data deposits may not be uniform. Example: although the project designs a uniform module and ask participants to use the standardized questions in their surveys, a number of collaborators choose to modify certain questions (one example is left-right placement of parties, which is nearly meaningless for respondents in Korea and Taiwan; hence participants have simply dropped certain questions from the module, creating missing values for those variables (Shivley, 2005). This may contribute to undermining the quality if the CSES data.

Also, this kind of crossnational research always must deal with problems of translation and comparability. CSES does not provide central translation facilities, so they are dependent on collaborators to translate the planning committee’s module into national language, and to provide CSES with an English-language version of their codebook. CSES most of the time uses simple translation (and not back-translation).

Electronic resource

CSES Variable list


Shively, W. Phillips. 2005. Democratic Design: The Comparative Study of Electoral Systems Project