Leader heuristics, political knowledge and voting in Britain's AV referendum

This paper uses data gathered in the British Election Study's 2011 AV Referendum Survey to investigate the impact of party leader images on referendum voting. The emphasis on leader images accords well with research showing that leader heuristics have sizable effects on voting in major referendums and general elections in Britain and other mature democracies. Reacting to these findings, some analysts have argued that the effects of leader images are heterogeneous, being stronger for voters with lower levels of political knowledge. In contrast, consistent with recent research in experimental economics and political psychology, it can be hypothesized that more knowledgeable voters rely more heavily on leader heuristics than do less knowledgeable individuals. Using multivariate statistical techniques developed for interpreting interaction effects in nonlinear models, analyses indicate that a political knowledge index focusing on the electoral system does not have statistically significant effects on referendum voting. However, voters' knowledge of leaders' positions on AV does interact with leader images. The analyses show that voters with higher levels of political knowledge are influenced more strongly by leader heuristics than are those who are less knowledgeable.

► Use BES CMS data to investigate voting in Britain's 2010 AV referendum.
► Use Ai and Norton's techniques to analyze interaction effects on AV voting.
► Leader image heuristics affect AV voting.
► Knowledge of leaders' positions on AV interacts with leader images.
► Leader heuristics have stronger effects on voting for knowledgeable voters.