The impact of a ‘safe seat’ on voter turnout and opinion polls

Media representation of a political party’s share in polls can shape voter behaviour and party performance. But how does this national information impact local election results?

Opinion polls began to capture British politicians’ attention in the 1950s, thanks to a rapid rise in the number of UK polling companies and their close ties to newspaper groups which turned their findings into headlines.

New CAGE research by Eleonora Alabrese and Thiemo Fetzer sheds light on the influence of pre-election polls on voter turnout particularly in a ‘winner takes all’ majoritarian electoral system.

The research draws on data between 1983 and 2017 from over 1000 national opinion polls and found that that voters were more likely to show party support in areas where there is a perceived competition - with turnout significantly lower in ‘safe seat’ areas.

The findings show that when combined with a measure of the ‘safeness’ of the constituency - the presence of a significant and pre-existent level of local electoral support for either Labour or the Conservative party - the margin of victory identified in national poll predictions significantly impacts voters’ willingness to show up at the ballot. This in turn affects the level of competition across different parties within a constituency, and hence their local chances of victory. The effect of polls on behaviour is also more distinct the nearer the poll is to the date of the election.

Commenting on the findings Professor Fetzer said:

“Pre-election polls are often a subject of political interest and debate. Our evidence demonstrates the role of the polls in shaping voter behaviour, party performance, and the implications of the demand for safe seats.

“In comparison to other EU countries there is a unique lack of bans on polls near election time in the UK and the US, where the perception of ‘safe seats’ already has an impact on voter mobilisation.”

The evidence of a causal link between poll predictions and voting intent underlines the importance of responsible reporting of polls. There is very little formal regulation of political polling in the UK - current OFCOM Link opens in a new window guidelines discourage the publication of opinion polls on polling day, while under Section 66A of the Representation of the People Act 1983 it is a criminal offence to report any information gained from an exit poll until after polls have closed, for fear of improperly influencing people’s voting decisions.

· Read the full research paper: Understanding the Impact of Pre-Election Polls on Voter Turnout and Demand for Safe Seats in the UK