Forecast update: 31 October 2014

Forecast b 141031 Continue reading Forecast update: 31 October 2014


After a year of forecasting, what’s changed?

Stephen Fisher, 24th October 2014

I first published a forecast of the 2015 general election result in October 2013. After taking on board comments and testing more candidate models, in February I revised the method from the one in this working paper to the one in this working paper. Both use opinion polls and election results going back to the 1950s to tell us what is likely to happen in this electoral cycle, and importantly, how sure we can be that it will happen. The historical pattern suggested governments tend to recover from mid-term blues while oppositions suffer a set back. Also the polls have tended to overestimate Labour and underestimate the Conservatives. Both factors suggested a Conservative lead at the next election. But also the variation in previous cycles was plenty enough to suggest very different outcomes were also possible if less likely.

Using a polling average for 8th October 2013 of Conservatives 32%, Labour 39% and Liberal Democrats 10% the revised method suggested a 42% chance of a Conservative overall majority. Over the last year the probability of a Conservative majority dropped steadily to 24% now. Why? Continue reading After a year of forecasting, what’s changed?