In recent decades, liberal democracies have considerably expanded the scope for citizen participation, calling their citizens to vote in a growing number of popular votes. This research investigates the effects of the rising election frequency on electoral participation. It theorizes which, when, and how past votes affect current voter turnout. We argue that all election types contribute to a common factor of election frequency, whose high values depress voter turnout and reduce the effectiveness of party mobilization even in the most important elections. We find support for the new theory using an original database of all significant elections and referendums held in twenty-two European democracies between 1939 and 2019, two natural experiments, and survey data from the Comparative Study of Electoral Systems. Our findings shed light on contemporary participation trends and have major implications for democratic citizenship and democratic institutional engineering.
