The Constituency-Level Elections Archive (CLEA) is a repository of detailed election results at the constituency level for lower chamber and upper chamber legislative elections from around the world. Our motivation is to preserve and consolidate these valuable data in one comprehensive and reliable resource that is ready for analysis and publicly available at no cost. This public good is expected to be of use to a range of audiences for research, education, and policy-making.


CLEA Release 12 (20181119) includes the launch of a new dataset with upper chamber election results at the constituency level. The lower chamber and upper chamber results are provided in separate data files. The existing CLEA dataset is now named CLEA Lower Chamber and the new dataset is named CLEA Upper Chamber. The same set of documentation applies to both datasets. Furthermore, party codes have been matched across the lower and upper chamber data. That is, if a certain party runs in both chambers then it receives the same party code in both datasets.

In addition, all datasets are are now in unicode (UTF -8) character encoding, which allows special characters and diacritics to be displayed correctly.

Overview of CLEA Release 12

CLEA Upper Chamber:
• Dataset includes 101 elections from 11 countries: Argentina, Bhutan, Bolivia, Chile, Mexico, Nigeria, Palau, Paraguay, Thailand, US, and Zimbabwe.
• US results from the first election by popular vote (1906) through 2016.

CLEA Lower Chamber:
• Dataset includes close to 1900 election results from 163 countries and territories.
• One new country: Belarus.
• Additions also include elections from Bulgaria, Croatia, Czech Republic, Guinea-Bissau, Honduras, Italy, Lithuania, Marshall Islands, Niger, and Norway.
• Additions also include results for upper-tier constituencies previously missing from existing Armenian, Japanese, and Nepali election results, and special constituencies for minorities missing from existing Colombian election results.

Effective Number of Parties and Party Nationalization Measures:
• The party nationalization datasets have been updated with data from this release.
• Party nationalization measures have been calculated for both CLEA Lower Chamber and CLEA Upper Chamber election results and are provided in separate files.
• For each chamber, the party nationalization measures are provided in three separate datasets that represent different levels of aggregation: national level, party level, and constituency level.
• Added new variable with number of constituencies in each election to aid with analyses.

The datasets are free and available for download in the following formats: Excel, Stata, SPSS, R, and SAS formats. Appendix II (Party Codes) is also available as an Excel file.

We'd like to thank our users for bringing errors and new data to our attention. These have been addressed in the latest release, and the list of changes and corrections can be found in the 'Data and Documentation' section of the website.


The co-directors of the CLEA project are:

Ken Kollman, University of Michigan
Allen Hicken, University of Michigan
Daniele Caramani, University of Zurich
David Backer, University of Maryland
David Lublin, American University

CLEA is grateful for support received from the National Science Foundation, the Taiwan Foundation for Democracy, the Center for Political Studies, the Director's Office of the Institute for Social Research, and the University of Michigan Office of Research and to the many contributors who provide election results and expertise.

This project would not be possible without the assistance of graduate and undergraduate students.