The impact of closeness on electoral participation exploiting the Italian double ballot system

We investigate whether the degree of political competition affects electoral turnout by using Italian municipal election data from 1993 to 2011. Relying on elections held using a double ballot system, we apply an instrumental variable technique exploiting the actual closeness between the two leading candidates in the first round as an instrument for closeness in the second round. The use of this strategy to estimate the impact of closeness on turnout is new to the literature. Controlling for municipal fixed effects and candidates’ characteristics, we find that expected closeness significantly increases turnout, thus supporting the idea that the expected benefits of voting increase in tighter political races. The estimated effect is much larger than that found when measuring closeness with ex-post electoral results, suggesting quite a relevant endogeneity bias in previous studies.