Thursday, May 25, 2017

Why We Should Treat Labour Polling Data With Caution


There has been a lot of talk recently about the narrowing of the polls and the increase in Labour's estimated vote share. However, when you look in more detail at the polls there is plenty of reason to treat the data with caution.

The chart above from Ipsos MORI shows that Labour's vote is much softer than the Conservative vote. 42% of those saying they will vote Labour say they may change their mind whereas the number is only 22% for the Conservatives.

Also Labour appear to be polling well because they are:
  • holding on to many Labour voters who dislike Corbyn
  • gaining new voters who previously didn't vote Labour but who like Corbyn
YouGov have produced the following analysis which found that 11% of voters that didn't vote Labour in the last election are Pro-Corbyn, almost half of Pro-Corbyn supporters.


I think it can be assumed that this 11% includes a lot of younger people and maybe some of those that voted Green or Liberal last time. Younger voters typically are less likely to vote so it may depend on how motivated they are to vote this time. The Independent reported that over a quarter of a million under 25s registered to vote on Monday this week. This might indicate that we will see a Corbyn effect in getting younger people to the polls.

However, even if more younger voters actually vote, Corbyn will still need to hang on to the 15% of people that voted Labour last time that are anti-Corbyn. It does appear that he could hang on to many these voters as a YouGov study found that 17% of people who say they will vote Labour also say they want Labour to lose, thus we can assume they are anti-Corbyn but holding their nose and voting Labour.

The other difficulty for Labour is that even if they poll better than they did at the last election they will still lose a lot more seats if the Conservatives pick up the former UKIP vote. An analysis by John Curtice suggests that the UKIP vote is moving almost exclusively to the Conservatives. As we can see below Leave voters in the referendum are heavily switching to the Conservatives.


What is also interesting in this analysis is that the Lib Dems are losing their support amongst Remain voters despite their strategy of focusing on a second referendum.

Overall, there are many reasons to be cautious about the rise in Labour support in the polls.