Ahead of the 2017 general election, I predicted that the opinion polls would be wrong again and that the Conservatives lead over Labour would be underestimated by 2.6%. I based this on data provided by Mark Pack who has systematically recorded every opinion poll published since 1945. In the event, I was right that the polls would be wrong but instead of an error favouring the Conservatives, the polls recorded the largest ever underestimate of the Labour vote. As a result, election forecasters were blindsided yet again and the result was a hung parliament which few saw coming.
My official prediction using my Final Election Model is that the Conservatives will make a net gain of 45 seats resulting in a working majority of 105 seats.
My forecast uses data from my latest UK Opinion Poll Tracker and it is worth reading that post in conjunction with this post. At the bottom of this post is a spreadsheet containing my prediction for each seat. I am basing all figures in this forecast on the assumption that Conservatives will have a 9.5% lead over Labour on June 8th. I arrive at that figure by taking the current CON-LAB lead of 7% in the latest polls and adding an expected 2.5% underestimate in the Conservative lead over Labour based on my analysis of historical polling errors. A knock-on effect of this assumption is that I expect turnout to be 2pts higher at 68%.
Unlike the 2015 general election when the polls were essentially static (& wrong) throughout the election, the 2017 general election has seen some of the most extraordinary volatility in the polls that I can remember. If you are a Conservative supporter, the narrowing lead over Labour must be leading to anxiety and changed underwear. If you are a Labour supporter, you are probably starting to dream “can we? will we?!” It doesn’t help that your state of mind will depend on which poll you are reading and your memories of the pollsters’ failure in 2015 so how can you make sense of what is going on. I will show you how in 5 steps and to heighten the drama, I will leave the punchline to the end!
For the last 6 weeks, I have been making forecasts of the number of seats that each party will get in the 2017 General Election. If you have been following my forecasts, you will know that I have developed a variety of prediction models which all predict something different. With 10 days to go, I decided it was high time to settle on a single Final Model which is described in this post.
This post was first published on 29th April 2017 and predicted a narrow Conservative Hold. I updated this post on 21st May 2017 to take into account latest data.
Welcome to the first of my constituency forecasts for the 2017 General Election. I’ve chosen to start with the seat of Bath currently held by the Conservatives for two reasons. First, it is where I live so I have a personal interest! Second, it is the bell-weather seat for the Liberal Democrats when it comes to the success of the anti-Brexit strategy. Fail to take Bath and they can kiss goodbye to any chance of making the election a success.
MY FORECAST – Lib Dem GAIN but still very marginal
As I have explained, I track the regional breakdowns to produce this chart. Every now and again, a full on poll takes place to explore a region in more detail and this allows me to check how good chart R1 is.
“I think the people in this country have had enough of experts”
Michael Gove, Sky News, 3rd June 2016
This was one of the most memorable quotes during the EU referendum in 2016 and came in response to a question as to why the forecasts of a whole list of organisations such as the IMF should be ignored. It prompted a flurry of rebuttals and articles supporting or damning him and the debate has not gone away.
Like so many quotes, it has already become distorted. I strongly recommend you listen to the full question and answer because here is his quote in its entirety.
When I read this full quote I realised I am in complete agreement with Michael Gove.
Ireland’s win over England brought the 2017 6 Nations to a close. England were crowned champions but were not able to top it with back to back grand slams. Over the last few weeks, I have been using the World Rugby Rankings to predict the outcome of the matches and now it is time to see how they performed.
The results are in and it is now time to review my predictions of the Copeland and Stoke-on-Trent Central by-elections. How well did my by-election model do and what lessons can be learnt? Let’s look at the numbers first.
Since the UK voted to leave the EU on 23rd June 2016, there have been 3 contested parliamentary by-elections (Witney, Richmond Park, Sleaford & North Hykeham) and one uncontested by-election (Batley & Spen which was the late Jo Cox’s seat). Many commentators have analysed these results to see how the referendum result has impacted on parliamentary voting intentions. Whatever voter dynamics are revealed, it is reasonable to assume that they are likely to influence future by-elections. In late October 2016 just after the Witney result, I realised it could be possible to build a by-election model by combining two sources of data.
- My own estimates of the Leave & Remain votes in each of the 650 parliamentary constituencies where I calculated that 400 out of 650 seats voted Leave.
- My interpretation of the Lord Ashcroft “exit poll” carried out on 21st to 23rd June 2016 and published immediately after the results were announced.
At the time, I described my by-election modelling approach in a youtube clip and that is worth listening to. I have made some changes to my model since then so this post is the most up to date version of my model. I will illustrate the basic principle using the Witney by-election (David Cameron’s former seat) of 20th October 2016 where the top line numbers are: