Category Archives: Combined forecast

Updated combined EU Referendum forecast

Stephen Fisher and Rosalind Shorrocks.

This week’s forecast shows a sharp drop in the probability of a Remain win to 60.6%, down from 67.7% last week. Similarly the forecast share of the vote for Remain has dropped from 53.8% to 52.7%. For the first time, our poll of polls of polls has Leave ahead, and more of the polls under consideration (see below for details) have had Leave ahead than have had Remain ahead. There has been little or no change in the expert forecasts and non-poll based models because of little or no new data. However there have been substantial changes in the betting and prediction markets, largely in response to the opinion polls. Intriguingly the volunteer forecasters at the Good Judgement Project now 72% chance to Remain, more than 10 points higher than the corresponding figure from the prediction markets: the biggest gap between these sources we’ve observed so far.

Remain % share Leave % share Probability Remain wins
Betting markets 51.5 48.5 60.7
Prediction markets 60.1
Citizen forecasts  52.0  48.0 64.4
Expert forecasts 55.1 44.9  62.0
Volunteer forecasts 54.2 45.8 72.2
Polls 49.6 50.4 45.7
Poll based models 51.0 49.0 59.0
Non-poll based models 55.6 44.4
Combined forecast (mean) 52.7 47.3 60.6

(Individual forecasts collected on 14th June 2016.)

METHODOLOGY Continue reading Updated combined EU Referendum forecast

Combined EU Referendum forecast update

Stephen Fisher and Rosalind Shorrocks.

This week’s forecast shows another drop in the probability of a Remain win, this time to 67.7%. Part of the reason for the drop is the introduction of significant new data sources and methodological changes (detailed below). But it is also true that all of the component methods, including those without methodological changes, have seen drops in the probability of a Remain vote. By contrast the forecast share of the vote for Remain continues to hover around 54% as in previous forecasts.

Remain % share Leave % share Probability Remain wins
Betting markets 53.2 46.8 72
Prediction markets 70.6
Citizen forecasts 64.3
Expert forecasts 55.1 44.9  62.0
Volunteer forecasts 54.2 45.8 74.2
Polls 51.1 48.9 59.1
Poll based models 53.5 46.5 72
Non-poll based models 55.6 44.4
Combined forecast (mean) 53.8 46.2 67.7

(Individual forecasts collected on 8th June 2016.)

METHODOLOGY Continue reading Combined EU Referendum forecast update

Updated combined EU Referendum forecast

Stephen Fisher and Rosalind Shorrocks.

This week’s forecast shows the probability of a Remain win reduced to 71.9%, down from 76.1% last week. Once again the forecast share of the vote for Remain, at 53.7%, is similar to all our previous combined forecasts.

Remain % share Leave % share Probability Remain wins
Betting markets 54.1 45.9 73.7
Prediction markets 73.8
Citizen forecasts 68.4
Expert forecasts 56.0 44.0
Volunteer forecasts 54.3 45.7 76.1
Polls 51.4 48.6 63.6
Poll based models 54.5 45.5 76.0
Non-poll based models 51.8 48.2
Combined forecast (mean) 53.7 46.3 71.9

(Individual forecasts collected in the morning of 1st June 2016.) Continue reading Updated combined EU Referendum forecast

EU referendum Combined Forecast Update

Stephen Fisher and Rosalind Shorrocks.

Our latest forecast based on combining other forecasts shows a big increase in the probability that Remain will win the referendum, from 70.5% last week to 76.1% today. Intriguingly this has only been accompanied by a small increase in the forecast share of the vote for Remain, from 53.8% in the last forecast to 54.3%.

Remain % share Leave % share Probability Remain wins
Betting markets 54.3 45.7 80.2
Prediction markets 79.1
Citizen forecasts 68.0
Expert forecasts 56.0 44.0
Volunteer forecasts 54.3 45.7 76.3
Polls 53.7 46.3 72.7
Poll based models 55.8 44.2 80.7
Non-poll based models 51.8 48.2
Combined forecast (mean) 54.3 45.7 76.1

(Individual forecasts collected in the evening of 24th May 2016.) Continue reading EU referendum Combined Forecast Update

Updated Combined EU Referendum Forecast

Stephen Fisher and Rosalind Shorrocks.

This is the latest of our weekly updates of our combined EU referendum forecast. There is once again very little change in the average forecast share of the vote, the average probability of a Remain win, or in any of the individual components of the forecast.

Share of the vote Remain Leave
Betting markets 54.4 45.6
Polls 52.1 47.9
Expert forecasts 56.0 44.0
Volunteer forecasts 54.2 45.8
Poll based models 54.6 45.4
Non-poll based models 51.8 48.2
Combined forecast (mean) 53.8 46.2
Probability that Remain wins
Citizen forecasts 68.2
Volunteer forecasts 73.7
Prediction markets 71.0
Betting markets 73.5
Polls 63.0
Poll based models 73.9
Combined forecast (mean) 70.5

Individual forecasts collected 17th May 2016. Continue reading Updated Combined EU Referendum Forecast

Updated Combined EU Referendum Forecast

Stephen Fisher and Rosalind Shorrocks.

This is the latest of our weekly updates of our combined EU referendum forecast. There is once again almost no change in the average forecast share of the vote or the average probability of a Remain win.

Share of the vote Remain Leave
Betting markets 54.3 45.7
Polls 51.3 48.7
Expert forecasts 56.0 44.0
Volunteer forecasts 54.3 45.7
Poll based models 55.0 45.0
Non-poll based models 52.0 48.0
Combined forecast (mean) 53.8 46.2
Probability that Remain wins
Citizen forecasts 68.5
Volunteer forecasts 74.0
Prediction markets 69.0
Betting markets 71.8
Polls 62.5
Poll based models 74.9
Combined forecast (mean) 69.8

Individual forecasts collected 10th May 2016. Continue reading Updated Combined EU Referendum Forecast

UPDATED COMBINED EU REFERENDUM FORECAST

Stephen Fisher and Rosalind Shorrocks

This is our latest update of our combined EU referendum forecast, updated weekly. There is no real change compared to last week in either the forecast share of the vote or average probability that Remain will win, with a clear consensus for a Remain win. This hides some movement in individual forecasts however, with the predicted probability of a Remain win from betting markets increasing, but decreasing from polls.

Share of the vote Remain Leave
Betting markets 54.6 45.4
Polls 51.3 48.7
Expert forecasts 56.2 43.8
Volunteer forecasts 54.8 45.2
Poll based models 55.4 44.6
Non-poll based models 52.0 48.0
Combined forecast (mean) 54 46
Probability that Remain wins
Citizen forecasts 67.9
Volunteer forecasts 74.0
Prediction markets 71.1
Betting markets 70.3
Polls 63.9
Poll based models 75.7
Combined forecast (mean) 69.3

Individual forecasts collected 3rd May 2016. Continue reading UPDATED COMBINED EU REFERENDUM FORECAST

COMBINED EU REFERENDUM FORECAST UPDATE

Stephen Fisher and Rosalind Shorrocks

Last week we launched a combined forecast method, which we will endeavour to update weekly. There is very little change since the last forecast. The average probability that Remain will win has gone up 3 points because all individual forecasts now suggest a higher probability compared to last week, but there is almost no change in the average forecast share of the vote. All methods still show a strong consensus pointing towards a Remain win.

Share of the vote Remain Leave
Betting markets 54.9 45.1
Polls 52.8 47.2
Expert forecasts 56.2 43.8
Volunteer forecasts 54.6 45.4
Poll based models 55.6 44.4
Non-poll based models 52.0 48.0
Combined forecast (mean) 54.3 45.7
Probability that Remain wins
Citizen forecasts 66.6
Volunteer forecasts 74.4
Prediction markets 72.0
Betting markets 67.2
Polls 68.8
Poll based models 76.4
Combined forecast (mean) 69.8

Individual forecasts collected 26th April. Continue reading COMBINED EU REFERENDUM FORECAST UPDATE

A combined forecast for the UK’s EU membership referendum

Stephen Fisher and Rosalind Shorrocks

There is a lot of evidence from the academic research on forecasting that suggests it is a good idea to combine information from different sources (e.g. here). In US and German elections generating a forecast by combining the forecasts of others has a good track record. For the upcoming US presidential election pollyvote.org provides an average of different forecasts together with excellent summaries and discussions of the different methods and forecasts.

We have developed a similar method of combining forecasts for the UK’s referendum on EU membership on 23rd June 2016. The summaries of the average forecast win-probability and share of the vote for Remain by method and then overall are presented in the tables below. Note that there are different components for each because some of the source forecasts provide only probabilities or only vote share.

Share of the vote Remain Leave
Combined forecast (mean) 53.6 46.4
Betting markets 53.9 46.1
Polls 51.4 48.6
Expert forecasts 56.0 44.0
Volunteer forecasts 54.6 45.5
Poll based models 54.0 46.0
Non-poll based models 52.0 48.0
Probability that Remain wins
Combined forecast (mean) 66.8
Citizen forecasts 64.3
Volunteer forecasts 71.2
Prediction markets 65.4
Betting markets 62.2
Polls 63.0
Poll based models 74.7

Continue reading A combined forecast for the UK’s EU membership referendum