Forecast UK is private project, started in 2008 by Peter Ould, to predict UK elections. Using a variety of statistical methods we try to provide point in time and future projection forecasts for UK General Elections and other national votes.
What is a Point in Time Forecast?
A Point in Time Forecast is a prediction based on the event happening at the moment of the forecast. A Point in Time Forecast will typically be based on recent opinion polling.
What is an Election Day / Forward Looking Forecast?
An Election Day Forecast is a prediction for the actual result of the election being analysed. An Election Day Forecast will typically be based on recent opinion poll trends, a statistical analysis of previous elections and movement in support before election day, and market expectations of the actual result.
Methodology
Our General Election forecasts take into account historically evidenced movements in party support in the run up to a General Election. This means that we can predict more accurately where we believe support will move between the date of the forecast and the actual election.
We assess all recent opinion polls, a bespoke sample of recent local election results (using data to analyse how local election results in the 12 months before a General Election can help predict the final result) and other barometers of sentiment as to the what the final result will be.
We run a monte carlo simulation of the election taking into account statistical analysis of the variance in support of parties. This helps us create a confidence interval for the actual final result, enabling us to report a “middle point” forecast and a band of possible outcomes.
We tend not to publish forecasts for individual seats as our model is focused on the overall position, and whilst we may not get individual seats correct, our methodology works very well taking the whole country together. We may publish information about individual seats if it is newsworthy.
Have you used these methods before / predicted other elections?
We have been predicting UK elections for over 15 years. At the 2017 General Election, we did better than all the other seat forecasts apart from the YouGov MRP poll (see here). At the 2019 General Election we were extremely close to the final exit poll and beat almost every other prediction.