By Elliot Hentov, Ph.D, Head of Policy Research, State Street Global Advisors
Should we all expect a stonking Conservative majority on the morning of 13 December? The most successful poll of the 2017 election was the YouGov MRP poll, which currently predicts a 68-strong Tory majority. Our own internal analysis adjusts for local dynamics and is more cautious, but still yields a 48-strong majority. Before drawing investment conclusions based on these expectations, it is worth examining where polls could go wrong on election day
There are two ways that existing polls could be right and yet still deliver a surprise. First, if expected turnout is wrong. Notably, turnout expectations were flawed heading into the 2016 referendum, as they did not project traditional non-voters to participate in large numbers, who then overwhelmingly voted to leave. In 2019, the same dynamic could only occur if historic turnout rates among certain demographics perform differently. Figure 1 illustrates how above-average turnout among younger age groups or below-average turnout among older age groups could deliver a different outcome from the polls.