How Campaigns Respond to Ballot Position: A New Mechanism for Order Effects

An established finding on ballot design is that top positions on the ballot improve the electoral performance of parties or candidates because voters respond behaviorally to salient information. This article presents evidence on an additional unexplored mechanism: campaigns, that can act before voters, can also adjust their behavior when allocated a top position on the ballot. We use a constituency-level lottery of ballot positions in Colombia to establish, first, that a ballot-order effect exists: campaigns randomly placed at the top earn more votes and seat shares. Second, we show that campaigns react to being placed on top of the ballot: they raise and spend more money on their campaign, and spending itself is correlated with higher vote shares. Our results provide the first evidence for a new mechanism of ballot-order effects examined in many previous studies.