Ballot position and election results: Evidence from a natural experiment

Candidates listed first on the ballot paper regularly receive more votes than other candidates, but what role does ballot layout play in this connection? Experimental studies from first-past-the-post systems show that the ballot position effect is causal as the order of names functions as a cue to voters. Does this also hold for PR systems where voters may vote for a party instead of a specific candidate? We identify a natural experiment in Danish local and regional elections involving more than 10,000 candidates on 103 different ballot papers using ballot layout to study ballot position effects. We find indeed, the ballot position/layout has a causal effect on election results in PR systems. Our findings indicate that the empirical domain of ballot position and layout effects is much wider than suggested by previous research.