This PhD thesis explores the question how citizens react when they are confronted with complex institutional questions related to politics. Specifically, we look at how citizens vote when they are asked for their opinion in a referendum on amending the electoral system of their country. Traditionally, electoral systems have been considered the political playing ground of political elites. It is hence interesting to see what happens when the ‘power of decision’ shifts to citizens, who are supposed to have little interest in, or knowledge about, electoral systems. We observe that citizens partially mimic political elites in their behaviour, by following partisan considerations: citizens judge electoral reforms on the consequences for their favoured parties. Moreover, citizens tend to incorporate values when judging electoral reforms: a particular effect is caused by the left-right-distinction, with left-wing voters being more attracted towards more proportional systems. Finally, we observe that how citizens react to electoral systems is affected by their baseline knowledge on politics. More knowledgeable citizens tend to judge more on substantial grounds, while less knowledgeable citizens rather tend to judge on miscellaneous grounds. We conclude by arguing that citizens can and do form substantial opinions on complex subjects like institutional reforms, but that some baseline knowledge is nonetheless required in order to substantially participate in the democratic decision-making process. / Doctorat en Sciences politiques et sociales / info:eu-repo/semantics/nonPublished