Boris Johnson is almost certainly returning to No 10by Paula Surridge / December 12, 2019 / Leave a comment
So, despite a day of rumours and speculation the exit poll confirms the broad picture that the final opinion polls painted yesterday. The Conservatives are expected to win 368 seats, more than enough for Boris Johnson to push ahead with his Brexit deal and take Britain out of the EU at the end of January. For those seeking some signs there may, yet, be hope of a different outcome the question is always “Is the exit poll right?” But based on the estimate tonight even the largest expected errors would not be enough to change the outcome.
Few who study or work in polling will forget where they were when they saw the 2015 exit poll. After weeks of polling showing it was too close to call, anticipation of a tense election night—anxiously waiting to see who would be able to form a government in the following days—was high. But as Big Ben chimed 10pm, the exit poll had found the Conservatives on course for a majority. Famously, the late Paddy Ashdown said he would “eat his hat’” if the prediction that the Liberal Democrats won just 10 seats proved correct—he was of course eating his words if not his hat by the following morning. Fast forward to 2017 and a similar shock result was announced: after beginning the campaign with a seemingly unassailable lead, the polling had showed this narrowing, but it was still largely predicting a small Conservative majority. However, the Conservatives found that this time the 10pm bongs revealed a lost majority.
After delivering two accurate but surprising predictions in a row, the exit poll has taken on something of a mystical quality, expectations about its veracity are high. But can it deliver when collecting the data on a cold December day as well as it has done in the milder days of June? The statistician behind the current methodology is clear that this depends on many things, not least a little bit of luck.
How does it work? The exit poll is not a traditional poll, it does not aim to find a representative sample of the electorate and infer behaviour from them. It works because it makes use of things we know, the election results from last time and the demographic…