Featuring Nate Silver, Robert Cahaly and Doug Rivers “Herd mentality” is never more real than during election season. In the bubble of opinion pollsters, pundits and the commentariat, a safe conventional wisdom usually forms about what is going to happen — and it is often wrong. Memories of 2016 haunt pundits, and there’s a high degree of emotion. So what is the evidence about who is going to win, and which way is the “herd” facing? Currently the national polls show Biden ahead by 6-8 points; in the battleground states that will decide the election it’s closer, but he’s still solidly ahead. Are the polls and media narrative more likely to be underplaying, or overplaying the chances of a Trump re-election? To find out, I spoke to some of the world’s leading experts — as well as one notable dissenting voice. Nate Silver runs FiveThirtyEight, perhaps the most famous polling website in the world; he faced a good deal of criticism after his 2016 eve-of-election model gave Hillary a 71.4% chance of winning the election (he’s keen to point out that this was lower than many other models — the New York Times had her at 85%). Right now, FiveThirtyEight gives Trump a 24% chance of winning, and Biden is at 76%. “It’s a weird election because it’s a little hard to diagnose exactly what the conventional wisdom is,” he tells me. “There's a meme that everybody is overconfident on Biden, but in fact... people are quite cautious on Biden.” But not everyone in Washington sees it that way. Republicans tend to think that the conventional wisdom is, once again, under-rating the chances of a Trump victory. The pollster-of-choice for this view is Robert Cahaly of Trafalgar Group. He may be a contrarian voice, but he deserves to be taken seriously: he was one of the few in 2016 to correctly call the crucial Trump wins in Michigan and Pennsylvania. His polls show Trump narrowly ahead, and winning enough of the battleground states to secure a victory in November. So how is it his numbers differ so dramatically? “We think what's happening is what's technically called the 'social desirability bias' — people give an answer to a question being asked by a live caller which is less about honesty and more about being judged positively by the person asking the question. So when there is a candidate who is polarising that it isn't politically correct to say you're for, you tend to give an answer that makes you look best... He estimates this “shy Trump” effect is between 3-5% and he suspects it could be more, and that “live caller” polling is the method in which the effect is strongest. It is not totally clear what methods Cahaly is using to assess the extent of the effect. He says it involves a combination of different polling methods (less reliance on live caller polls, more digital and robocalls) and asking additional questions such as “who do you think the majority of your neighbours are for?” to ascertain people’s true motivations. But the complexity of the method raises legitimate questions. Another problem with this theory is that if such a “shy Trump” effect were a big factor, you would expect to see it most powerfully in districts that are overwhelmingly Democratic, and where being a Trump supporter was most shameful — in highly Democratic parts of California, for example. Trump should have outperformed his polls there in 2016; but in fact the reverse happened. Clinton did even better than the polls suggested she would in those highly Democratic areas, and Trump outperformed in strongly pro-Trump areas. In theory, those polling companies that do not use a live caller method should mitigate any “shy Trump” effect because you are not talking to a real person, but that’s not happening either. Doug Rivers is Chief Scientist at YouGov, an online-only pollster that makes use of its large panel of survey respondents: “Hundreds of thousands of people have signed up to take surveys and we interview them repeatedly over time. What that enables us to see is the same people at different points in time and whether they've changed or not. What we've seen is about 7% of the Trump voters now say they will vote for Biden rather than Trump, and there's only a 1% offsetting flow in the other direction. So that's a big deal...  As Nate Silver says, "If I were looking to play the markets and I didn't have an ethical problem with doing it, I would think the price on Biden is very favourable." Doug Rivers agrees: "I think the betting markets, which are showing this about 50/50, are underestimating the chances of a Biden win." So is Donald Trump toast? "Not quite,” Doug replies, “but close - he's browning rapidly."