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Related projects

The CEP is integrated in two international projects based in the USA, namely the CSES (Comparative Study of Election Systems) as well as the CNEP (Comparative National Elections Project), giving a comparative dimension to the data collected in Portugal, and ensuring its dissemination.


CSES ( is the largest network of electoral studies in the world, aggregating European, American, Asian and African post-electoral surveys. Based in Michigan, USA, CSES was founded in 2001. Since its foundation, six questionnaires have been released, which on average have been implemented in around forty countries each, allowing for a better understanding of how people vote today. Each questionnaire includes central questions that remain unchanged, and thematic questions which vary. The creation of this set of integrated datasets gave rise to a large number of publications. 


The Comparative National Elections Project (CNEP) (  is a partnership among scholars who have conducted election surveys on five continents. Founded in the late 1980s, it now includes 63 surveys from 1990 to 2021 in 30 different countries. The CEP participated in the CNEP twice, namely in the 2005 and 2015 legislative election studies.


The CEP is integrated into the MEDEM infrastructure ( a pan-European network of data collection centres, which aims to provide resources, facilities and support for high quality research into all aspects of the democratic electoral process in Europe.

Other Related Projects


Surveys ICS / ISCTE ( is a collaboration between the Institute of Social Sciences of the University of Lisbon (ICS-ULisboa), the ISCTE – Instituto Universitário de Lisboa (ISCTE-IUL) and the Impresa Publishing S.A. group, namely through SIC and Expresso. This collaboration aims to collect, process and disseminate data on the attitudes and political behavior of the Portuguese population, through the carrying out of opinion studies (polls) using representative samples of the population.

European electoral behaviour projects

European Elections Study

True European Voter