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Record W4409493677 · doi:10.1080/21642850.2025.2490550

What nudges you to take a vaccine? Understanding behavioural drivers of COVID-19 vaccinations using large-scale experiments in the G-7 countries

2025· article· en· W4409493677 on OpenAlexaffabout
Manu Savani, Sanchayan Banerjee, Andrew Hunter, Peter John, Richard Koenig, Blake Lee‐Whiting, Peter Loewen, John McAndrews, Brendan Nyhan

Bibliographic record

VenueHealth Psychology and Behavioral Medicine · 2025
Typearticle
Languageen
FieldSocial Sciences
TopicVaccine Coverage and Hesitancy
Canadian institutionsMcMaster UniversityUniversity of Toronto
FundersBritish Academy
KeywordsNudge theoryCoronavirus disease 2019 (COVID-19)Scale (ratio)2019-20 coronavirus outbreakSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2)VaccinationVirologyPsychologyMedicineGeographySocial psychologyOutbreak

Abstract

fetched live from OpenAlex

Introduction We present a unique multi-country, two-wave dataset of 42,417 survey responses drawn from nationally representative samples of citizens from the G-7 countries: Canada, France, Germany, Italy, Japan, UK, and USA. This data note outlines the motivation and methodology of the survey instrument and describes the measures contained in the dataset. We highlight areas for future research.Methods We fielded an online survey over two waves (January 27 to February 26 [n = 24,303] and wave 2 from March 6 to May 12 [n = 18,114]) measuring a range of demographic, social, political, and psychological variables. Samples were nationally representative by age, education, gender, and subnational region. Each wave included of three experiments (one conjoint and two between-subjects) to facilitate randomised evaluation of behavioural health policies promoting the uptake of COVID-19 booster vaccinations.Results The dataset has produced two peer-reviewed publications at the time of writing ([Banerjee, S., John, P., Nyhan, B., Hunter, A., Koenig, R., Lee-Whiting, B., Loewen, P. J., McAndrews, J., & Savani, M. M. (2024). Thinking about default enrollment lowers vaccination intentions and public support in G7 countries. PNAS Nexus, 3(4), pgae093]; [Koenig, R., Savani, M. M., Lee-Whiting, B., McAndrews, J., Banerjee, S., Hunter, A., John, P., Loewen, P. J., & Nyhan, B. (2024). Public support for more stringent vaccine policies increases with vaccine effectiveness. Scientific Reports, 14(1), 1748]). A summary report is posted online (https://www.thebritishacademy.ac.uk/publications/overcoming-barriers-to-vaccination-by-empowering-citizens-to-make-deliberate-choices/). Additional research outputs are currently under preparation.Discussion Our dataset combines observational and experimental data on behavioural health policies, offering numerous insights. First, the dataset's extensive size and geographical diversity enables comparative analysis of public health issues involving social, political, and behavioural factors. Second, the dataset is suited to advanced statistical methods that can explore heterogeneity in the uptake of behavioural health policies, such as vaccine nudges. Third, the timing of the data collection, coinciding with the rise of the Omicron variant, provides valuable insights into why some previously vaccinated individuals might hesitate to receive additional doses, potentially improving our understanding of the COVID-19 pandemic and possible responses to pandemics and other public health emergencies in the future.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.021
metaresearch head score (Gemma)0.040
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.021
Threshold uncertainty score0.112

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0210.040
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0010.001
Bibliometrics0.0000.001
Science and technology studies0.0010.002
Scholarly communication0.0020.002
Open science0.0010.001
Research integrity0.0020.002
Insufficient payload (model declined to judge)0.0060.001

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.227
GPT teacher head0.524
Teacher spread0.297 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

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Citations1
Published2025
Admission routes2
Has abstractyes

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