And the effect seems to hold even when participants are told information is biasedby Zacharias Maniadis / November 15, 2019 / Leave a comment
As an election looms in the UK and a presidential vote approaches in the US next year, opinion polls are everywhere. Citizens will have to navigate a lot of noise as they decide which party or candidate to choose.
As our research has found, the way citizens receive information about polls through the media can affect the outcome of elections. We conducted several laboratory experiments to test whether voting behaviour is affected by biased reporting of poll results. The results suggest it is.
In our experiments, we asked 375 student volunteers to vote in a series of elections, choosing between two parties—party K and party J. They did so under two conditions: an unbiased control condition, where they saw all polls, and a biased treatment condition, where they saw only the polls where party K’s popularity was the highest. The biased scenario conferred a considerable benefit to party K. In it, party K won 80 per cent of the time. In the control scenario, the party won only 60 per cent of the time (this relatively high proportion was due to pure chance).
In another experiment, we explicitly informed participants beforehand that they would be receiving biased information about the polls. Remarkably, party K still gained considerably from the existence of the bias, winning 64 per cent of the time compared to 57 per cent in an unbiased setting. Even when our voters knew they were receiving biased information, they didn’t seem to discount it enough when casting their vote.
Does media slant matter?
This all suggests that election results in democratic countries could be sensitive to biases in the way that the traditional media reports poll results.
The traditional media selects which polls to emphasise from a large pool of results. Sometimes outlets do this with an eye to make interesting news or pander to the expectations of the public. The latter means that journalists may decide not to publish a poll showing an unexpected result, for example, even if they believe it to be true, out of concern that readers might see them as less credible.
In our research, we also found that social media propagates poll results in a biased way.…