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 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

Forecasting Local Election Seats 2016

by Stephen Fisher

Local elections are supposed to be about local matters, but the electoral fortunes of councillors and would-be councillors depend very heavily on the popularity of their parties nationally. So the outcome of this year’s local elections depend on how the current standing of the parties compares with four years ago when the seats up for election this year were last contested.

In the run up to the 2012 local elections Labour were polling above 40% with a solid 9 point lead over the Conservatives, in part because of the so-called omnishambles budget. Meanwhile the Liberal Democrats had slumped in the polls after the formation of the coalition government with little over 11%.

According to the average of the most recent polls from six companies, Labour have dropped since 2012 to 35% now, only narrowly ahead of the Conservatives who are on 34%. The Liberal Democrats have slid even further to just 7%. On this basis alone we should expect both Labour and the Lib Dems to lose substantial numbers of council seats while the Conservatives should make gains from their 3-point recovery. Continue reading Forecasting Local Election Seats 2016

Second forecast for the Brexit referendum

by Stephen Fisher and Alan Renwick

A month ago we issued our first forecast for the EU membership referendum on 23rd June 2016. Based on an analysis of referendums in the UK and on the EU outside the UK, and on vote intention opinion polls we forecast that Remain had an 87% chance of winning, and that Remain would get 58% of the vote, plus or minus 14. This was in part based on our polling average (excluding Don’t Knows) of 55% for Remain on 11th March.

Our current forecast suggests the contest is a fair bit closer. Our polling average now puts Remain on 52%. We now give Remain a 73% chance of winning and estimate that the Remain share of the vote will be 54% plus or minus 13 points.

The key change here is the drop from 55% to 52% Remain in the polling average. The main reasons for this are as much or more methodological than substantive. Continue reading Second forecast for the Brexit referendum