Turnout

UK General Elections #7 – How accurate are voting intention polls? – Revised

June 8, 2024 By Nigel Marriott

Voting intention polls in the UK are accurate after all!

For years, I’ve observed that UK polls on average underestimate the Conservative vote and overestimate Labour’s vote. When I converted poll data into forecasts of seats won, I had to first estimate how much polling error there would be. So what’s changed? It turns out I was comparing polls to the wrong statistic, namely national vote share. The correct comparator is in fact average vote share per seat.

UK General Election 2024 #1 – Going beyond the swing

February 18, 2024 By Nigel Marriott

Labour is on course for a crushing landslide later this year… or are they? Many parallels with 1997 are being drawn at the moment but it’s too early to be making detailed forecasts. Instead, I want to lay the foundations for my election forecast later this year by looking at what 100 years of UK electoral history is telling me. I tell this story by assigning probabilities to 10 specific outcomes of interest and finish by explaining why 2024 is more likely to be a repeat of 2001 than 1997.

I remind you I was deemed the most accurate forecaster of the 2019 general election. This article is the first in what I hope will be a series of articles which lead me to hold on to that accolade!