University of Bayreuth, Presse release No. 181/2022 - 07 November 2022
Bavarian local elections 2020: Strong increase in turnout in run-off elections worked in favour of incumbents
In March 2020, the statewide mayoral elections in Bavaria took place under unusual conditions: Due to the Covid-19 pandemic, participation in the second round of voting was only possible by absentee ballot. A research team led by Bayreuth political economist Prof. Dr. David Stadelmann conducted a statistical analysis of these elections. The study, published in the journal "Economics & Politics", came to the following conclusion: The postal vote, which was made convenient and free of charge for all eligible voters, increased voter turnout statewide by more than ten percentage points. This increase benefited incumbents seeking re-election.
On 15 March 2020, the first round of local elections in Bavaria took place – on schedule and without restrictions on in-person voting. At that point, the Covid-19 pandemic was still in its early stages. Just one day later, however, the Bavarian government declared a state of emergency and imposed lockdown measures. The second round of voting then took place as planned on 29 March 2020, but due to the Bavarian state government's arrangements, only postal voting was possible. Ballots along with postage paid return envelopes were sent directly to all eligible voters.
In a first step, the authors of the study examined the effect of absentee voting on voter turnout. They compared the difference in turnout between the first and second ballots in 2020 with the differences in turnout in previous ballots. This revealed that turnout in 2020 increased unusually compared to previous second ballots – by more than ten percentage points statewide. "Such a large increase in turnout in runoff elections has not been seen before in German local politics on this scale. In the previous Bavarian local elections in 2008 and 2014, turnout in the second rounds was lower than in the first round. In the last mayoral election in 2020, however, turnout increased statewide in the second ballot. We can assume that this increase in 2020 was almost entirely due to the fact that absentee voting made it convenient for all eligible voters to participate in the runoff elections without any additional effort. Local peculiarities, such as close competition for office of mayor or varying popularity ratings of the candidates, on the other hand, played no role in the increase in voter turnout. This was a rare but particularly favourable constellation for investigating how such an increase in voter turnout as such affects the election results," explained Marco Frank, first author of the study and a researcher with Prof. Stadelmann at the University of Bayreuth.
Using modern econometric methods, the team then investigated the question of whether incumbents running for re-election benefited from the increase in voter turnout. The calculations prove just that: They show that the unexpected increase in turnout, which is not related to any specific features of local political competition or the popularity ratings of candidates, systematically and significantly increases the incumbents' advantages. "A 10-percentage-point increase in turnout that is unrelated to local political characteristics leads, on average, to a statistically robust 3.4-percentage-point increase in the vote share for incumbent mayors. If local political competition is rather weak, their share of the vote even increases by more than five percentage points," said Prof. Stadelmann, summarizing the main results of the study. Accordingly, some incumbents may not have been re-elected at all if there had not been the higher voter turnout resulting from the absentee ballot.
In their analysis of the 2020 Bavarian mayoral elections, the study's authors also found that the increase in voter turnout, which was independent of local political factors, did not affect the outcome of the runoff elections in a gender-neutral way: Male incumbents benefited slightly more from this increase than female mayors seeking re-election
Marco Frank, David Stadelmann, Benno Torgler: Higher turnout increases incumbency advantages: Evidence from mayoral elections. Economics & Politics (2022),