10 Downing Street: who’s next? Seemingly unrelated regressions to forecast UK election results

In recent years, the British polling industry has encountered difficulties in its attempts to measure voting intentions in important popular consultations, notably the 2014 referendum on Scottish independence, the 2015 UK general election, and the 2016 EU membership referendum. In such a context, it is extremely valuable to explore how different forecasting models that rely on political and economic variables can be used to predict the outcome of elections. In this paper, we propose such a model by introducing a political economy equation to estimate the vote share obtained by the incumbent party in UK general elections three months before the vote as well as a set of seemingly unrelated regressions (SUR) to forecast the results of the Official Opposition, the Liberal Democrats, and the remaining parties.