Policy information and opinion change: panel studies from European Union referendums

Do citizens use substantive information about the implications of new policies when forming opinions on political proposals? While a wealth of research has paid attention to this fundamental question, we know surprisingly little about whether policy information matters to citizens’ issue opinions in the real world. I present a panel study of the three most recent European Union referendums in Denmark and the UK Brexit referendum where certain policy information became salient during the campaigns. By utilising panel survey data collected at different stages of these campaigns, I show that voters who learned about the positive (negative) implications of adopting the referendum proposals became markedly more inclined to increase (decrease) their support for the proposals relative to voters who stayed uninformed. These findings advance the extant, largely experimental literature on the influence of policy information in public opinion formation.