The Effects of Voting Advice Applications: New Experimental Evidence

Increasingly large numbers of voters turn to Voting Advice Applications (VAAs) to acquire information on how close different parties or candidates are to them on policy issues. However, despite significant scholarly attention, it remains unclear whether VAAs affect their users’ political knowledge, preferences, and behavior. We present new causal evidence on VAA effects based on a novel experimental design which addresses several weaknesses of previous studies. Focusing on the 2024 UK General Election (N = 3,350), we find that VAA usage significantly increased participants’ knowledge of relative policy proximity and affected their party preferences. These effects are strongest in the short run, but remain visible after the election and translate into changed behavior at the ballot box among undecided voters. A simultaneous field experiment (N = 29,000) suggests that these effects are likely to generalize to real-world behavior. Yet, we do not find evidence for an effect on electoral turnout.