Ballot Order Effects and Party Responses: Evidence from Lotteries in Colombia

Ballot positions often affect the electoral performance of parties. Existing theories for this effect focus on voter-specific behavioral explanations. We present evidence on an additional unexplored mechanism: parties adjust their behavior to account for their position on the ballot. This adjustment matters for how we interpret existing results. First, we use a constituency level lottery of ballot positions across two elections and 1971 races in Colombia. We find evidence for a ballot position effect of 6.7 percent on vote share, and 8.8 percent on seat share. Second, we show that parties raise and spend more money on their campaigns if they are allocated a top spot on the ballot. Finally, we show that campaign spending is correlated with higher vote shares. Our results suggest that the existing literature may be overstating the contribution of the voter behavioral channel on ballot order effects.