Information, fact checking and voting for the far-right: Evidence from an RCT around a general election.

Last registered on March 19, 2024


Trial Information

General Information

Information, fact checking and voting for the far-right: Evidence from an RCT around a general election.
Initial registration date
March 11, 2024

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
March 19, 2024, 4:52 PM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.



Primary Investigator

Universidad Carlos III de Madrid

Other Primary Investigator(s)

PI Affiliation
Norwegian Business School
PI Affiliation
PI Affiliation

Additional Trial Information

On going
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
The recent rise of the far-right, particularly in European democracies, has motivated a sizeable body of research on the determinants of voting for such parties, which often rely on inflammatory statements that may or not be factual.

In this project, we provide respondents from a representative sample of eligible voters in the 2022 general election with statements from, or about, members of a far-right party on different subjects, and provide them additional context that validates or disproves the statements. We study whether the subject of the statement, and the provision of additional context symmetrically affect perceptions of respondents about the credibility of the statements, and the members of the party, as well as the effect of the statements and corresponding context on voting behaviour in a general election.

To this effect, we survey respondents both before and after the election. We also study how sociodemographic and political characteristics of potential voters (e.g. being undecided in the week prior to the election) may condition the effect of the statements (or the context provided) affects the propensity to vote, and the probability of voting for certain parties.
External Link(s)

Registration Citation

Fernandes, Jorge et al. 2024. "Information, fact checking and voting for the far-right: Evidence from an RCT around a general election. ." AEA RCT Registry. March 19.
Experimental Details


We provide quotes from, or about, politicians associated to a far-right party, about four subjects, that have been fact checked by mainstream media. Importantly, these quotes comprise both statements that have been fact-checked to be true or false.

Some respondents receive additional context, besides the quote, that is an abridged version of the fact check. In any case, all quotes and context are factual, and not manipulated by the research team. We also provide the official sources which are used to validate or disprove the quote. All information provided is publicly available.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Probability to vote for a party running for election; turnout; voting decision (post-election);
Credibility of information; Effect of context provision on credibility of information and candidates.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Impact of election outcomes on interest in politics, satisfaction with democracy and trust in the electoral process.
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Respondents are split into groups, according to the subjects of the information provided, whether they receive just the quotes, or the quotes and additional context, and whether the quote has been fact-checked to be true or false. The control group receives no information.
Experimental Design Details
Treatment bundles are comprised of two big groups:
Group 1: Quotes on Corruption, Health care and Poverty/Living conditions
Group 2: Quotes on Immigration, Health care and Poverty/Living conditions

Each group is then sub-divided into receiving quotes that have been fact-checked to be true or false (comparable, on the same subjects), and subsequently divided into a group which receives the additional context or not. In total there are 8 treatment arms. The analysis will group these arms depending on the outcome of interest.
Randomization Method
Randomization done in qualtrics.
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
Sample size: planned number of observations
2700, representative of the Portuguese population eligible to vote in the election.
Sample size (or number of clusters) by treatment arms
300 by treatment arm
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
Nova School of Business and Economics Institutional Review Board
IRB Approval Date
IRB Approval Number
Approval Reference #2024100


Post Trial Information

Study Withdrawal

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Is the intervention completed?
Data Collection Complete
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials