Incumbents tend to have an advantage in elections. This has been shown by a large literature, and is a concern since it may prevent the best candidate from winning.
When we say ‘best’, we are using a broad definition of candidate quality, encompassing personal characteristics (for instance, how qualified they are and how impervious to corruption) as well as how closely their positions align with their constituents. Ideally, democratic systems will allow the best candidate to win, regardless of whether they currently hold office or have name recognition with voters. Democratic systems are weaker when incumbents enjoy advantages that allow them to get re-elected regardless of quality.
When incumbents are harder to remove, electoral turnovers are less likely, which is also a concern. Using data from national elections conducted worldwide since 1945, Marx et al. (2022 and 2023) find that turnovers lead to improvements in governance, economic performance, and other measures of national health. So, to the extent that the incumbency advantage prevents turnovers from taking place, it may further weaken democracy and governance.
Evidence of an incumbency advantage in the US House of Representatives goes back decades (Erikson 1971, Gersbach 2012). A number of papers use quasi-experimental methods to measure the advantage. Lee (2008) uses a regression discontinuity design (RDD) in close US elections, comparing parties that barely win to those that barely lose. The paper shows that the incumbent party is upwards of 40 percentage points more likely to win elections than the non-incumbent party. The method and results of that study were replicated in other contexts with similar results (e.g. Fowler and Hall 2014), as well as in other countries, from Canada (Kendall and Rekkas 2012) to Norway (Fiva and Rohr 2018).
In a new paper (Dano et al. 2022), five of us examine for the first time the intersection of incumbency and another potential advantage: the ability to coordinate and clear the field of ideologically similar candidates who could potentially split the vote.
The coordination effect
In elections with more than two candidates, it is important to solve coordination problems, lest the outcome undermine the representativeness of the election. This is particularly relevant in countries with multiparty systems.
To understand the importance of coordination, consider an election with two candidates on the left, each of them supported by 30% of voters, and one candidate on the right, supported by 40% of voters. If the two parties on the left do not coordinate and agree to ask one of their candidates to drop out – and voters on the left do not manage to coordinate on their end to rally behind only one of the two candidates – then the right-wing candidate may end up winning, even though they are clearly the least representative of the electorate.
From a theoretical standpoint, it is unclear who stands to benefit more from coordination. The incumbent may use the political power of being in office to prevent ideologically close candidates from running. Or the challengers may have learned a lesson from their defeat in the previous election, and coordinate to win the next.
The literature has less to say about the coordination effect than the incumbency advantage. A study by Anagol and Fujiwara (2016) shows that parties and voters in elections in Brazil, India, and Canada tend to coordinate on behalf of candidates who barely placed second in the previous election, so that these candidates are more likely than barely third-place candidates to contest, and win, subsequent elections. Pons and Tricaud (2018) document coordination failures in French elections: they show that when a third candidate makes it into the second round, their presence harms the candidate ideologically closest to them and causes their defeat in one fifth of the races – a result driven by voters who value voting expressively (for the candidate they genuinely prefer) over coordinating. Using a method resembling Anagol and Fujiwara (2016), we show (in Granzier et al. 2022) that past rankings can be a powerful coordination device both for parties and voters.
Our new paper is the first to bring the incumbency advantage and coordination effects together.
Coordination failures compound the incumbency advantage – but how?
Our study focuses on French local and parliamentary elections, which use a two-round plurality voting rule and feature a large number of candidates in the first round. We employ an RDD in a sample of more than 20,000 of these races, comparing candidates who just win or just lose an election, and the pool of candidates they face in the next election, as well as their own chances of winning.
First, we find that a large incumbency advantage exists.
Then, in our main finding, we show that a close victory reduces competition from ideologically similar candidates and leads the victor to a stronger performance in the next cycle. Incumbents are 33 percentage points more likely than their closest challenger to compete again in the next election, and they face (on average) 0.43 fewer competitors who share their orientation. Overall, a candidate’s victory increases their likelihood of winning the next election by 25.1 percentage points.
So, coordination is taking place, and more effectively on the side of the incumbent, compounding the incumbency advantage. But is coordination on the part of the campaigns – meaning the parties and candidates – or on the part of voters? The answer appears to be both.
Evidence that parties and candidates coordinate
We find that the reduction in competition from challengers who share the incumbent’s political orientation is driven by the dropout rate of candidates affiliated with political parties, not by unaffiliated challengers. We interpret this as evidence of communication between the parties, rather than the incumbent exerting pressure on others to drop out; otherwise, we would see the same frequency of dropouts among unaffiliated candidates.
Once the campaigns have coordinated on a field of candidates, it is the voters’ turn. Will voters coordinate to the incumbent’s advantage (rallying behind someone familiar) or to the advantage of challengers?
Here, we have two pieces of evidence, both of which point to an advantage for the incumbent.
Incumbents are able to run more original campaigns
Incumbents might have more resources and run better campaigns. We explore this first by looking at campaign expenditures, and find no solid evidence; and second, by using text analysis to examine and compare the content of digitised two-page candidate manifestos mailed by the state to all registered voters. We find that incumbents’ manifestos are more original, where manifesto originality is defined relative to other candidates from the same party. The latter result suggests that incumbents’ communication strategies are more personalised and better tailored to their voters’ preferences.
Candidates gain name recognition that benefits them in future elections
We run a separate RDD that measures the impact of qualifying for the runoff on the next elections’ results, using the same sample of elections. Unlike winning the election (and becoming the incumbent), qualifying for the runoff has no effect on the number of competitors with the same orientation in the next election. However, it does increase candidates’ future vote share. This effect indicates that candidates who do well in an election gain name recognition for voters, and is consistent with the hypothesis that incumbency advantage is driven by voters’ behaviour as well.
Our results may weigh into decisions made by policymakers, candidates, and voters.
Policymakers in many countries discuss which voting rules are best, and sometimes change rules to make elections more representative (Cantoni et al. 2022). To inform such decisions, scholars design election overhauls that might overcome the incumbency advantage (Gersbach 2016). The fact that coordination gives incumbents yet another advantage may weigh in policymakers’ decisions to even the playing field for challengers.
For candidates and parties, particularly on the losing-side, it is important to note that coordination gives incumbents a leg up, and perhaps be more proactive in communicating about when to bow out of a contest for the good of the party’s ideals.
Finally, voters supporting challengers in multi-party systems may face the choice to vote with their heart or with their head. They should be aware that the incumbent has a hidden advantage, and that it can be overcome through coordination.
Anagol, S and T Fujiwara (2016), “The runner-up effect”, Journal of Political Economy 124(4): 927–991.
Cantoni, E, V Pons and V McIntyre (2022), “What Do We Know About Voting Procedures? Lessons for Policy”, UPPER Policy Brief.
Dano, K, F Ferlenga, V Galasso, C Le Pennec and V Pons (2022), “Coordination and Incumbency Advantage in Multi-Party Systems-Evidence from French Elections”, CEPR Discussion Paper 17600.
Erikson, R S (1971), “The Advantage of Incumbency in Congressional Elections”, Polity 3(3): 395–405.
Fiva, J, and H L Røhr (2018), “Climbing the ranks: Incumbency effects in party-list systems”, European Economic Review 101(C): 142–156.
Fowler, A and A B Hall (2014), “Disentangling the Personal and Partisan Incumbency Advantages: Evidence from Close Elections and Term Limits”, Quarterly Journal of Political Science 9(4): 501–531.
Gersbach, H (2012), “Raising the bar for incumbents”, VoxEU.org, 3 Jan.
Gersbach, H (2016), “History-bound re-elections”, VoxEU.org, 27 Feb.
Granzier, R, V Pons and C Tricaud (2022), “The large effects of a small win: How past rankings shape the behavior of voters and candidates”, American Economic Review: Applied Economics, forthcoming.
Kendall, C, and M Rekkas (2012), “Incumbency advantages in the Canadian Parliament”, Canadian Journal of Economics/Revue canadienne d’économique 45(4): 1560–1585.
Lee, D S (2008), “Randomized experiments from non-random selection in U.S. House elections”, Journal of Econometrics 142(2): 675–697.
Marx, B, V Pons and V Rollet (2022), “The surprising benefits of voting for change”, VoxEU.org, 16 May.
Marx, B, V Pons and V Rollet (2023), “Electoral Turnovers”, CEPR Discussion Paper 17047.
Pons, V and C Tricaud (2018), “Expressive voting and its cost: Evidence from runoffs with two or three candidates”, Econometrica 86(5): 1621–1649.