So the moment you’ve been waiting for, Ben’s 2024 Election Prediction for the UK General Election.

It won’t be any surprise to tell you that Labour are going to win in a huge landslide… but my suspicion is that it won’t be as big as most people think.

 

Here is Electoral Calculus’ final prediction (excluding Northern Ireland)

 

There are two ways of polling people- the more traditional method, firstly, is we ask a random bunch of people throughout the country, and try to make sure they are representative of the population. Unfortunately they often aren’t, so we have to use post-stratification to try and adjust the sample. So if we sample 1000 people and 60% are men, and 40% are women, we upweight the women to get the right sample. This is what many polling companies do, and it introduces some errors. The main problem these days is getting people to answer the surveys, normally online, and there is an inherent bias in who is prepared to do the surveys. If more people who answer surveys are of one political persuasion, correcting this bias is hard. How often do you answer a survey?

Electoral calculus takes an average of recent polls, so it’s probably as good as it gets- and then applies an algorithm where it assumes that changes since the last election are uniform across the country, with just a couple of fiddle factors. It views the UK (well, Great Britain) as one homogenous blob- when of course there are local issues- but hopes it evens out.

 

Many polling organisations do a similar thing, and there are some variations on their predictions. Note the large differences! (from wikipedia)

 

To correct this, many companies have launched a vastly improved polling method, called MRP – multilevel regression and poststratification- which corrects for asking the wrong people, but also uses demographic factors and asks people which constituency they are in to try and get a view of how each constituency will vote. So if someone in a poor constituency voted conservative last time, and votes labour this time, they kind of assume that this will to a certain extent happen in other like constituencies. It requires more assumptions but in general should be more accurate. The difficulty here is that it requires vastly more people- tens of thousands- so is expensive, and the exact assumptions used are not published openly. So how do we check it? We can’t.  It’s interesting that different companies have vastly different results whilst polling- although note the long polling period.

 

Another large factor is that polling companies often ask people about their likelihood to vote- and only include those that say they are certain to vote in the sample. But people often lie- in the last general election 80% said they would vote, and only 69% did: https://x.com/CameronGarrett_/status/1808838766867448179

 

My feeling is that there will be a lot of younger people who actually don’t vote, and said thay will: older people vote by routine, and many of them will have had postal votes, so I think this favours the conservatives and routine voters. Not hugely, but small percentage changes make a big difference in votes. And none of the polling is going to catch this.

 

Finally, the electoral boundaries have shifted 

 Essentially we are guessing what people will do at a local level- so another large uncertainty.

 

So because I think essentially polls are overanalyzing people’s likelihood to vote, particularly for younger and therefore more left wing parties, and also because I think the MRP polls are not picking up an upswing in late reform votes, here is my final prediction. Yes it’s a guess, but basically we are all guessing!

 

Labour 399

Conservative 114

Reform 20

Green 3

Lib Dems 75

SNP 15

Corbyn 1

Speaker 1

Plaid 4

Giving Labour a majority of about 148 depending on how you count it.