UK 2015 – Forecast – 18th February 2015


This is the latest of our forecasts for the UK General Election in 2015. To see our methodology click here. To read a note on our updated forward looking projection methodology, click here.

Why have you not produced a forecast for three weeks?

We have been analysing the last month’s worth of polling data to come to a final conclusion as to whether opinion movements in the run up to the May vote are similar to those before previous elections. We have now come to the conclusion that the normal movements in the three main parties before a general election are not occuring in 2015. On the basis of this of this observation we are no longer applying an algorithmic adjustment to party support and variance. Instead we are applying a simple movement in support based on observed shifts in party support in the past few months.

Forecast

Our mid point and confidence interval forecast for seats is as follows.

Party Seats – Mid Point Seats 50% CI Seats 95% CI
Conservatives 296 284 – 308 252 – 332
Labour 287 272 – 302 244 – 325
Liberal Democrats 11 8 – 15 6 – 24
UKIP 0 0 – 4 0 – 29
SNP 32 15 – 48 5 – 58
PC 3 1 – 3 0 – 4
Others inc. Green (GB) 4 2 – 5 1 – 17
Irish 18 n/a n/a

Our mid point and confidence interval forecast for votes (mainland GB) is as follows.

Party Vote% – Mid Point Vote% 50% CI Vote% 95% CI
Conservatives 33.1 31.8 – 34.2 29.4 – 36.9
Labour 32.6 31.8 – 33.4 30.4 – 34.8
Liberal Democrats 10.7 9.8 – 11.6 7.9 – 13.6
UKIP 13.0 11.2 – 15.2 7.3 – 19.4
Green 5.1 3.9 – 6.4 1.7 – 8.5

Our probability of different outcomes is as follows.

Event Probability
Conservative Majority 3.9%
Conservative Minority 54.5%
Exact Tie Labour and Conservative 1.5%
Labour Minority 38.3%
Labour Majority 1.8%
UKIP more votes than Liberal Democrats 75.5%
Greens more votes than Liberal Democrats 1.9%
Greens more votes than UKIP 0.8%
Green > LD > UKIP (votes) 0.1%
LD > Green > UKIP (votes) 0.7%
LD > UKIP > Green (votes) 23.8%
UKIP > Green > LD (votes) 1.8%
UKIP > LD > Green (votes) 73.6%
UKIP get more votes than Labour 0%
SNP largest party in Scotland (seats) 58.1%

What are the main points of your forecast?

We identify the following events / features.

  • We continue to see a decline in the support for UKIP – we now show a 50% confidence interval of between 0 and 4 seats for May 2015.
  • Although the Conservatives lose seats to Labour, Labour lose a significant number in Scotland to the SNP, all but destroying their chance of a workable plurality. We are now treating the SNP surge in Scotland as consistent and lasting.
  • The Liberal Democrats will struggle to poll significantly above 12%. This will have a dramatic effect on their attempts to retain seats. Furthermore, recent constituency level polling indicates that the expected Liberal Democrat incumbency effect is not as strong as has been thought.

The key aspect of our forecast is uncertainty. We now show a variance of possibilities from a Labour majority to a Conservative majority. We still believe the most likely outcome is a Conservative minority government.

What improvements are you hoping to implement next?

At the moment the model isn’t taking into account polling in individual seats. As such data becomes richer and more available we will attempt to use it.

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