2019 Constituency Polls Accuracy

How accurate were constituency polls in the 2019 UK Election?

Before the 2019 UK General Election, research companies conducted over 30 constituency polls.

This article seeks to understand the methods of constituency polling, and their accuracy. The analysis finds a decline in mean absolute error as the election approaches. This is in line with national polling.

Methods

The British Polling Council said 2019 was “more accurate” than any election since 2005. This was for national polling. This analysis will look at constituency polling.

A constituency poll must meet the following criteria:

• Target population: The target population must be one constituency.
• British Polling Council: The company must be a British Polling Council member.
• Fieldwork date: The survey fieldwork end-date must be after 1st October 2019.

This analysis does not look at constituency projections from national polls. Nor does it include MRP estimates.

Deltapoll

Deltapoll collected its responses by telephone, from landline and mobile numbers. The company calibrated responses to the profile of adults (18+) in each constituency. The weights were for gender, age, ethnicity, ward, a 2017 past vote recall target, and the 2016 EU referendum.