In recent years, political science research has devoted extensive attention to voter turnout. However, only a few studies have focused on those voters who go to the polling station to cast an invalid vote (i.e., blank and null votes). This group of voters is relevant in the study of any democracy, but they are all the more relevant in Belgium where voting is compulsory. In such contexts, invalid votes allow us to better understand the electorate’s behaviour. First, we explore in detail the nature of invalid votes. Do we observe that null ballots are deliberate and that voters meant to spoil their ballot? Or do we observe that ballots have been invalidated because of a mistake by the voter? If it is the latter, how many invalid votes are intentional and how many are unintentional? Second, it allows us to study the factors influencing the share of blank and null votes. By analysing the share of null and blank votes across municipalities, we consider possibilities as to where such votes are more frequent and how the local political context may influence the quantity of such ballots. These elements would directly contribute to enriching the literature beyond the mere dichotomy between voters and abstainers.
The study of blank and null votes contributes to current political debates about democracy. It allows us to look at whether the complexity of the party system has an impact on the number of invalid votes, or whether the municipality’s socio-economic context matters. It could also lead to the reopening of the debate on how best to inform voters so that they better understand the rules of the electoral system, in other words, how to cast a ballot. Another important contribution of this article relates to the ongoing debate that opposes those who defend electronic voting to those who prefer paper voting in Belgium. Whereas the Flanders and Brussels regions apply electronic voting, Wallonia has fully shifted back to paper ballots. Our analyses thus contribute to the discussion of how these changes may have an impact on the quantity and types of invalid ballots cast.