UK Election Forecasting Theory, Techniques and Controversial Discussions

This page will provide detailed information about the techniques and science used when forecasting UK-Elections, and will also highlight some of the past and continuing discussions on this sometimes controversial subject.

As a start, here are some links to some election-related academic and other sources of information and debate.

Academic and Theoretical Sources

• Election Forecasting in the UK Academic paper by Clive Payne from 2001, discusses UK Election forecasting generally, and reviews the various statistical methods used by the BBC to forecast different types of election in the UK in the previous thirty years.
  
• Exit polling in a cold climate: the BBC-ITV experience in Britain in 2005 Academic paper by John Curtice and David Firth, provides an excellent discussion about election-poll related matters, drawing on the experiences of the BBC/ITN exit pollsters in 2005. This paper includes a mention of the Curtice/Firth method for calculating seat win probabilities.
  
• Polls and the Vote in Britain Academic paper by Christopher Wlezien, Will Jennings, Stephen Fisher, Robert Ford and Mark Pickup discussing the evolution of electoral sentiment over British electoral cycles. Contends that polls from early in the electoral cycle contain much information about the final outcome.
  
• Predictable and unpredictable changes in party support: A method for long-range daily election forecasting from opinion polls Academic paper by Stephen Fisher, outlines several methods for forecasting the next British general election on a daily basis from twenty months prior using opinion polls. Stephen's website is elections etc.
  
• Back to Swing: Explaining uniformity and non-uniformity Article by David Voas in which he examines the evidence in support of Uniform National Swing, and finds it to be still quite strong.
  
• Strong Transition Model Article on his Electoral Calculus website by Martin Baxter explaining in detail the "Strong Transition Model" technique he uses for forecasting. (In UK-Elect terminology his model is a form of Proportional Loss With (20%) Threshold). Martin's website is electoral calculus.
  

Discussions and Debates on UK Election Forecasting (warning: can get heated!)

• The 2010: UNS, Proportional Swing and all that... Useful comparison on the PoliticalBetting.com site: Dr Rob Ford, Dr Will Jennings, Dr Mark Pickup and Professor Christopher Wiezen reflect upon models and methods for projecting the vote at the 2010 British Election. Includes a summary showing how accurate the various methods (and several websites) were at predicting the 2010 election.
• Ford: Our Model vs. 538 Political Scientist Robert Ford's explanation (on the www.Pollster.com site) of how the PoliticsHome UK poll tracking and seat projection model used in 2010 differs from the model developed by Nate Silver and his colleagues at FiveThirtyEight.com
• Nerdfight - UK Election Methodology Defence by Nate Silver of the techniques he was using to predict the 2010 UK General Election
• Wonk Wars: how does your model swing? Useful summary by Alex Barker on the FT Westminster Blog of the Nate Silver / Robert Ford debate (with further links, requires FT access)
• UNS discussion on PolicalBetting Article by Andy Cooke on the Political Betting website about Uniform National Swing (Part 1)
• UNS discussion on PolicalBetting Article by Andy Cooke on the Political Betting website about Uniform National Swing (Part 2)
• UNS discussion on PolicalBetting Article by Andy Cooke on the Political Betting website about Uniform National Swing (Part 3)
• Uniform Vs Proportional Swing - Which is Best? Comparison on the Liberal Democrat Voice site by Mark Pack, "Presenting a new analysis of the merits of the two main ways of converting party vote shares into seat number projections"

See Also:

• Detailed information about UK-Elect forecasting techniques
• Latest UK-Elect Election Forecast
• Previous UK Election Results