British Remainers watched the US presidential campaign with an uneasy sense that they had seen it all before: brazen lies from a populist movement, experts lining up to attest that all sensible people agree on what should be done . . . Those of us who saw the EU referendum campaign up close have been well prepared for the possibility of a Trump victory. US Democrats had less of a visceral warning and so were more surprised.
The truth is that once Trump had secured the nomination, a Trump presidency was always a strong possibility. The betting markets seemed to recognise this, offering odds of three-to-one a week or so before the poll. Three-to-one shots happen all the time — or at least, about a quarter of the time. A defeat for Hillary Clinton may be far more consequential than a defeat for Manchester City and, therefore, far more shocking but it shouldn’t be any more surprising. Favourites do not always win.
Forecasting is a tough job but we make it harder than it has to be by committing some familiar cognitive errors. So what are the lessons that we should learn?