The dark side of proportionality: Conditional effects of proportional features on turnout

• Division of powers increase the participatory gap across levels of education and interest.
• Participation in divided systems is even lower at low values of education and interest.
• Proportional features increase participation only among those with more cognitive resources.

Past research analysing the positive effects of proportional systems on electoral participation has focused on dimensions such as quality of representation, mobilisation, competitiveness, and efficacy. However, the potential consequences of higher complexity and difficulties for accountability on proportional systems are not well known. We show that proportional features capturing complexity and dispersion of power can increase the participatory gap between citizens with high and low education and interest in politics, usually by depressing turnout among the less educated and interested. The implications of adopting proportional rules that result in complex and divided forms of government in an era of increasingly disengaged citizens are discussed.