When one side stays home: A joint model of turnout and vote choice

Most existing studies of referendums examine voter turnout and their vote choice separately. Our theoretical model suggests that this is problematic. The model predicts that voters who generally prefer one of the two possible referendum outcomes, but who are relatively uncertain about the consequences of their preferred option, tend to abstain from voting. Greater uncertainty about a referendum option not only reduces its value, but also, for more "distant" voters, the value of participating. Uncertainty, thus, has a double effect: potential supporters of one referendum option are less likely to vote; and citizens who vote are less likely to support this option. We use data from the 'Brexit' vote to show how individual assessments of uncertainty about the two-options affect turnout and the vote. Our empirical analyses provide support for our theoretical model.