|CSES is a collaborative program of research among election study teams from around the world. The research program as well as the questionnaire and the study design are developed by an international committee of leading social researchers. Participating countries include a common module of survey questions in their post-election studies. The data contain information on individual choice behavior, demographics, the constituencies, the national election results and the political systems. The studies are then merged into a single, free, public dataset for use in comparative study and cross-level analysis.