From polls to votes to seats: Forecasting the 2010 British general election

This paper outlines and discusses techniques for three stages in forecasting parliamentary seats from British opinion polls: adjusting and aggregating published vote-intention figures from across different polls; forecasting how public opinion might change before election day; and predicting the seat totals from the forecasted election-day vote shares. Specifically, we consider a state-space model for opinion polls which correct for house effects and other sources of survey error, the estimation of the historical relationship between polls and the election-day share of the vote, and a probabilistic approach to predicting the winner in each constituency.