The impact of campaign pledges on voter decision-making
Campaign promises, or pledges, are a staple of any democratic election cycle. “Voters use pledges to select between candidates and parties and to keep them accountable after the election,” says Carsten Jensen(opens in new window), a political scientist at Aarhus University(opens in new window). “Without pledges, voters would be left with much less information.” But do voters decide based on the election pledges political parties make? “Although this is a key assumption in most democratic theories and, seemingly, among parties who issue dozens of pledges during campaigns, the scientific literature does not provide a clear answer to this question,” adds Jensen. Helping to bring clarity to the issue is the EU-funded PLEDGEDEM project.
Gathering data on voter behaviour
With the goal of determining whether election pledges actually matter, the project, which received support from the European Research Council(opens in new window), dug into the data. “Reliable data on voter behaviour is notoriously hard to come by,” explains Jensen, who coordinates the project. “That’s why we opted to use two innovative datasets that, together, provide us with an unbiased estimate of voters’ awareness and use of pledges.” The first dataset consists of panel surveys with embedded conjoint experiments conducted both before and after national elections. The second dataset codes all the collected pledges made during an election, noting whether they were kept or broken and how the mass media reported on them. “What makes this two-pronged approach so unique is that it allows us to study the electoral effects of pledges in real time as the campaign unfolds,” notes Jensen.
The limited impact of political pledges
With this data in hand, the project determined that political pledges have a rather limited impact on voter behaviour. “Despite the many dozens – sometimes even hundreds – of pledges each party makes, they rarely sway how an individual votes,” remarks Jensen. For example, during the 2019 Danish national election campaign, researchers estimated that the most salient pledges affected voter choice by between 1.1 and 2.1 % (averaged across the electorate). However, despite their minimal impact, Jensen is quick to point out that this doesn’t mean pledges are inconsequential. “While modest, these effects can be decisive in the often highly competitive context of modern elections,” he says.
Ulterior motives for campaign pledges
If campaign pledges have such a limited impact on voters, why do political parties continue to make them? One theory is that these pledges aren’t intended for voters but for other audiences altogether, such as interest groups. Or perhaps they are used to garner media attention that could help a party standout in an increasingly competitive political landscape? “This would all have major implications on our understanding of political behaviour, party politics and normative theories of democracy, and thus deserves to be explored further,” concludes Jensen. The project is currently conducting research on such issues.
