Do Voting Advice Applications Have Durable Causal Effects?: Evidence from Concurrent Survey and Field Experiments

Micha Germann; Iulia Cioroianu; Fernando Mendez; Constantinos Djouvas

doi:10.1017/S1475676526101753

Do Voting Advice Applications Have Durable Causal Effects? Evidence from Concurrent Survey and Field Experiments

Micha Germann
, Iulia Cioroianu
, Fernando Mendez
, Constantinos Djouvas

University of Zurich
Cyprus University of Technology

Research output: Contribution to journal › Article › peer-review

Abstract

Voting advice applications (VAAs) are used by millions of voters, yet their causal effects on political knowledge, preferences, and behavior remain unclear. We present new evidence from two experiments conducted during the 2024 UK General Election: (1) a panel survey experiment that provides access to participants’ VAA advice, achieves high compliance with treatment assignment, and allows us to track outcomes over time; and (2) a concurrent field experiment embedded in a real-world VAA that allows us to assess the ecological validity of our findings. We find that VAA usage leads to durable changes in voters’ perception of how close they are to parties on policy issues, shifts party preferences in line with the advice received, and affects the vote choices of undecided voters. These results suggest that VAAs play an important role in election campaigns. However, we find no evidence that VAAs increase electoral participation.

Original language	English
Number of pages	21
Journal	European Journal of Political Research
Early online date	25 Sept 2026
DOIs	https://doi.org/10.1017/S1475676526101753
Publication status	E-pub ahead of print - 25 Sept 2026

Data Availability Statement

All data and statistical code necessary for replicating the analyses reported in this paper can be accessed in the Harvard Dataverse at https://doi.org/10.7910/DVN/L8TTA9.

Acknowledgements

We would like to thank Jonathan Wheatley, Matthew Wall, Susan Banducci, Ailsa Henderson, Fraser McMillan, Roula Nezi, Ed Poole, Vasiliki Triga, and Richard Wyn Jones for their help with the development of WhoGetsMyVote. For excellent research assistance, we would like to thank Helen Bramah, Louis Bromfield, Keiron Burgess, Lucija Cepo, Sean Garrett, Tom Gibson, Danielle Joyce, Ellen Kear, Bella Longdon, Megan Salter, Ryan Whitehead, and Eva Whyte. Earlier versions of this paper were presented at the 2025 ECPR General Conference and research seminars and workshops at the University of Bath, the University of Southampton, and the University of Zurich.

Funding

This research was supported by the Economic and Social Research Council (grant numbers: ESRCIAAFF018 and ES/W000598/1).

Keywords

Voting advice applications
party preferences
electoral participation
political knowledge
randomized experiment

Access to Document

10.1017/S1475676526101753Licence: CC BY

Cite this

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title = "Do Voting Advice Applications Have Durable Causal Effects?: Evidence from Concurrent Survey and Field Experiments",

abstract = "Voting advice applications (VAAs) are used by millions of voters, yet their causal effects on political knowledge, preferences, and behavior remain unclear. We present new evidence from two experiments conducted during the 2024 UK General Election: (1) a panel survey experiment that provides access to participants{\textquoteright} VAA advice, achieves high compliance with treatment assignment, and allows us to track outcomes over time; and (2) a concurrent field experiment embedded in a real-world VAA that allows us to assess the ecological validity of our findings. We find that VAA usage leads to durable changes in voters{\textquoteright} perception of how close they are to parties on policy issues, shifts party preferences in line with the advice received, and affects the vote choices of undecided voters. These results suggest that VAAs play an important role in election campaigns. However, we find no evidence that VAAs increase electoral participation.",

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AU - Djouvas, Constantinos

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AB - Voting advice applications (VAAs) are used by millions of voters, yet their causal effects on political knowledge, preferences, and behavior remain unclear. We present new evidence from two experiments conducted during the 2024 UK General Election: (1) a panel survey experiment that provides access to participants’ VAA advice, achieves high compliance with treatment assignment, and allows us to track outcomes over time; and (2) a concurrent field experiment embedded in a real-world VAA that allows us to assess the ecological validity of our findings. We find that VAA usage leads to durable changes in voters’ perception of how close they are to parties on policy issues, shifts party preferences in line with the advice received, and affects the vote choices of undecided voters. These results suggest that VAAs play an important role in election campaigns. However, we find no evidence that VAAs increase electoral participation.

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