The UK Political Studies Association today (3 June) released the results of its survey of expert predictions of the 2016 EU referendum. The full report, Expert Predictions of the 2016 EU Referendum: a survey by Will Jennings and Stephen Fisher on behalf of the U.K. Political Studies Association, is available to download here.

The survey was distributed to members of the Association as well as a large number of survey researchers from major polling companies in Britain and to journalists from the print and broadcast media. We asked respondents to share their predictions of the outcome, the probability of Britain voting leaving the EU, the final vote shares for each side, and the level of turnout.

  • An overwhelming majority of our experts thought the UK is more likely to vote to stay in the EU than to vote to leave. 87% of our respondents said that Remain is more likely to win. Just 5% thought that Leave is more likely to triumph. The remaining 8% were of the view that the two sides have an equal chance of winning.
  • The strong consensus that Remain is most likely to prevail conceals considerable doubts. On average, our experts believed that there was a 38% probability of Britain voting to leave the EU. This finding suggests much more uncertainty over the outcome than the responses to our binary choice question about which side is most likely to win. Moreover, our experts were noticeably more uncertain about the outcome than participants in prediction and betting markets, which have recently been suggesting just a 26% chance of a Leave vote.
  • The average prediction of the vote share for Remain was 55%, while that for Leave was 45%. These were also the most common predictions and they mirror the result of the Scottish Independence referendum in 2014.  
  • The predictions of our three expert groups differ very little across the worlds of academia, journalism and polling, though political scientists put the odds of a Brexit vote very slightly higher, at 38%, than journalists, at 32%.
  • Finally, the average prediction for turnout at the referendum was 61%. This is below the 66% turnout at the general election in May 2015 and far below the 85% achieved at the Scottish Independence referendum.

 

The results of this survey should be interpreted in light of the poor forecasting performance of a similar expert survey of predictions for the 2015 general election. Then, as now, the views of the experts were broadly in line with prevailing expectations of the time. In the run up to the 2015 general election the experts were expecting a close result on votes and seats between the Conservatives and Labour, with 94% expecting a hung parliament. The full report from 2015 is available here.

Will Jennings, Professor of Political Science and Public Policy at the University of Southampton and Trustee of the Political Studies Association observed:

“Experts from the worlds of academia, opinion polling, and the media overwhelmingly think that Remain are likely to win this month’s referendum, but their predictions suggest the result is still in doubt. On average they think there is a 38% chance Britain will vote to leave the EU.”

“Our experts are not convinced that the referendum campaign has fully captured public interest, as they are predicting turnout that is over 20 percentage points lower than that for the Scottish Independence referendum,” added Professor Jennings.

The following are key tables for the report on our Expert Survey:

The survey elicited responses from 496 academics, 13 pollsters, 33 journalists and 54 people from other backgrounds. The fieldwork was conducted between 24th May and 2nd June 2016.

 

For further details of the PSA Expert Survey, please contact:

Will Jennings: email w.j.jennings@soton.ac.uk, phone 07713 624487

Stefanie Mair, Political Studies Association: email stefanie.mair@psa.ac.uk, phone 0207 321 2545.