From Harvard University
Polls and past electoral results may shape beliefs on candidates’ chances and affect their decision to run as well as voters’ choices. We isolate the impact of candidates’ rankings using an RDD in French local and parliamentary elections, where up to 3 or 4 candidates can qualify for the second round. Candidates who barely finish first in the first round are more likely to run in the second round (4.7pp), win (7.6 pp), and win conditionally on running (5.1 to 7.6pp), than those who barely finish second. The effects of finishing second instead of third are even larger (8.9, 20.4, and 6.5 to 10.9pp), and finishing third instead of fourth also increases the likelihood to run in the second round (13.1pp). These results are largest when the candidates are of the same political affiliation (making coordination relatively more important and desirable), but they remain strong when two candidates only qualify for the second round (and there is no need for coordination), showing a large bandwagon effect.