Election 2017: how the UK voted in 7 charts

Did the Leave vote prove decisive?

It is impossible to discuss the dynamics at play in this election without considering the fallout from the EU referendum. Brexit may have become less prominent in the latter weeks of campaigning, but it still looms large over the political landscape and will undoubtedly have played on many voters’ minds at the ballot box on Thursday.

One leading theory was that Leave-voting Labour areas may have become fertile ground for the Conservatives to make gains, so to what extent did this prove to be true?

With almost all seats reporting, the statistical association between a constituency’s “Labour Leave vote” — an admittedly rough metric calculated by multiplying the 2015 Labour vote by the Leave vote — and that constituency’s swing from Labour to the Conservatives proved to be strong.

The impact of health

One new entrant to the conversation on the dynamics that affect political allegiances is health. An FT analysis found that healthier people were more likely to vote for Emmanuel Macron in the French presidential election, and The Economist demonstrated that poor health was correlated with support for Donald Trump last November.

Preliminary results suggest that health is playing a role in the realignment in British politics, too. The Conservatives have fared better relative to Labour in constituencies where a high share of people report being in poor health.

This may initially seem counter-intuitive — Labour is after all the party of the National Health Service — but the key to understanding the role of health is to view it not as a specific and immediate concern for individuals but instead as a proxy for overall wellbeing and social status.

The share of a constituency’s population in poor health is strongly associated with the share of its population in the lowest social class (as measured by the NRS DE social grade, which includes people in semi- and low-skilled jobs or unemployment), so we may be seeing here a sign of the much-touted Tory encroachment into the working-class demographic that has traditionally voted overwhelmingly for Labour.

Our analysis finds that the link between a Tory/Labour swing and health is slightly stronger than the relationship with the DE social grade alone, so it may be that the impact of chronic poor health on attitudes and outlook may also make people more likely to vote Conservative than Labour, all other things being equal.

Education, education, education

Demographic analysis of voting patterns in the EU referendum or the US or French presidential elections have highlighted the role of education in the political divide between leftwing or centrist causes and the right.

In short: better-educated people tend to vote for leftwing or centrist causes, while those who never went to university are more likely to vote for rightwing or populist parties.

This UK general election is fought between a more fragmented set of adversaries, which means education was never likely to drive quite such a stark wedge between any two camps, but nevertheless its role is clear.

The Conservatives have gained working-class votes. And yet the narrative of this election is one of a Tory failure. So where is the exodus of Conservative voters to counteract that blue-collar boost? The answer is: in well-educated areas.

The higher the share of people in a constituency who have a degree, the larger the swing from the Conservatives to Labour.

The eagle-eyed among you may now be thinking, “Ah, but younger people are more likely than their elders to attend university, so might this not just be a proxy for the role of age?”.

First of all, good question. But in this case we have specifically used the share of people aged over 50 who have a degree, to get rid of as much as possible of the hidden role of age. As you can see, the pattern holds.

Interestingly, though, the role of education is reversed after adjusting for a set of other key demographic and social factors. Once “Labour Leavers”, health and the percentage of people without a passport are accounted for, higher levels of education are actually associated with a higher swing to the Conservatives.

This suggests that university attendance is tied up with social class and attitudes — a theory the FT has explored previously— and that it is those other characteristics that are driving shifts between Labour and the Conservatives.

With those overlapping factors dealt with, having a degree is as much a signifier of coming from a wealthy background as anything else, which explains why it would be positively associated with a pro-Conservative swing.

Who benefited from the Ukip collapse

One narrative that emerged as the campaign wore on was the mass migration of 2015 Ukip voters to the Conservatives. A tipping point came in early May when more 2015 Ukip supporters said they intended to vote for Theresa May’s party than Paul Nuttall’s.

In the final days of the campaign, Labour appeared to be getting a Ukip boost of their own, suggesting the benefits might be spread equally between both parties, but the results suggest the Tories were the clear winners in this regard.

On a seat-by-seat basis, Ukip losses were extremely closely associated with Conservative gains, and the relationship grows even stronger after adjusting for the EU referendum result.

The implication is that Ukip was, as some had suggested, a “gateway drug” for people who had voted for leftwing and centrist parties before 2015, turned to Ukip in 2015, and have now ended up with the Conservatives.

Election day polling from Lord Ashcroft also supports this conclusion: 57 per cent of 2015 Ukip voters went Conservative on Thursday, compared with 18 per cent who voted Labour.

Ukip had previously taken 28 per cent of its 2015 supporters from the Conservatives and 10 per cent from Labour, so if the 2017 trajectories prove correct, this would demonstrate a considerable net gain for the Tories via the Ukip route over the seven years since the 2010 election.

The same data demonstrate Labour’s secret to success this time around: the party picked up votes from all other parties in similar numbers, and fared similarly among different demographics.

This lack of a pattern to their gains along clear political or demographic dividing lines may be the clearest sign yet of a “Corbyn factor”, whereby people of all stripes simply became more likely to vote Labour as the campaign wore on, won over by a campaign and leader that seemed to be gaining momentum while their opponents stumbled.

The polarising forces in British politics are changing

Not so long ago, class was the starkest dividing line in British politics and society at large. In the October 1974 general election, 56 per cent of middle-class voters backed the Conservatives, compared with just 19 per cent who voted Labour. A few rungs below them on the social ladder, the lower working classes voted in almost the polar opposite manner: 57 per cent backed Labour, 22 per cent went Conservative.

Across the electorate as a whole, Labour won 40 per cent of the vote to the Tories’ 37 per cent. Another way of saying this is that the middle classes were 40 percentage points more pro-Conservative than the electorate as a whole, and the lower working classes were 32 points more pro-Labour: a total partisan gulf between the classes of 72 points.

But fast-forward 43 years to today, and the gap has plummeted to just 15 per cent. According to Lord Ashcroft’s poll, the Conservatives beat Labour by three points among middle class voters in 2017 — bang in line with the overall figure — while lower working-class voters were 15 points more pro-Labour than the overall average.

This represents a remarkable redrawing — or perhaps erasing — of the dividing lines of class. With the Labour party increasingly appealing to educated, cosmopolitan city dwellers, and the middle class itself simultaneously becoming ever more urbanised, voting Conservative is simply not the natural move it once was for this demographic.

At the other end of the spectrum, working-class voters increasingly make their political moves based on socially conservative rather than economically liberal views, resulting in a weakening of their once unquestioned ties to Labour, and a gradual acceptability — perhaps via a couple of years with Ukip — of voting Conservative.

But if class no longer divides Britons at the ballot box, another characteristic has stepped into its place: age.

Younger voters have always tended to lean Labour, and older voters Conservative, but for more than 20 years from 1987 to 2010, these partisan leanings remained small and stable.

But in the last seven years a yawning gap has opened up. In 2010, 18-to-24s broke just one point in favour of Labour, while over-65s favoured the Tories by 13 points. But in 2017 young voters broke in a landslide to Labour, backing Jeremy Corbyn’s party over the Tories by 51 points more than the national average.

And polarisation is not just for the young: over-65s favoured Theresa May’s party by 35 points — 32 more than the average for the electorate. In just seven years the partisan age gap has shot up from 14 points to 83.

Early figures this year suggest that young people turned out in force on Thursday. If they feel their efforts were rewarded, a simultaneous ramping up of youth engagement and age-based polarisation could create a heated political debate for years to come.

Politics is political

Slicing and dicing the results by demographics and social characteristics can give us a good idea of the dynamics at play in an election, but the existing political landscape in each seat plays an important role, too, given the tactical nature of voting in Britain.

Using only the demographic and socio-economic characteristics of each seat, a model combining various variables predicts around 65 per cent of the swing between Labour and the Conservatives in any given constituency.

Adding in the existing political context in the form a data on the previous winner and runner-up of a seat, and adjusting for the different nature of politics in different regions, raises the explanatory power of the model to 75 per cent.

Did the parties spread their votes efficiently?

Some of the excitement around a possible “Corbyn surge” as Labour ate into the Tory poll lead was tempered by concerns that Labour may indeed gain votes, but only in seats where it was already comfortably in front.

The early evidence is that these worries were misplaced: many of Labour’s biggest swings against the Tories came in marginal seats, with minimal padding of healthy leads.

The party either overturned or significantly reduced the Conservative margin even in places like Canterbury, which has voted Conservative since 1918.

Labour has also widened its lead in areas where its 2015 margin was precarious, such as Ealing Central and Acton. The chart below shows how Labour has performed against the Conservatives in seats where they and the Conservatives were the top two parties in 2015.

There had been fears that Labour would gain votes in safe seats. Darker red dots and lines show greater changes in the Conservative-Labour margin. Many of the reddest constituencies had margins of around 10 percentage points in 2015.

How did the modellers fare?

Ahead of the election various pollsters, academics and analysts modelled the likely distribution of seats based on polling and the demographics of each constituency. Most projected large Conservative majorities, but pollsters YouGov were an outlier in predicting a hung parliament.

Here’s how all the models compare to the exit poll:

Technically, the exit poll is itself a projection, so how much can we trust its top line numbers at this stage?

As the FT’s elections analyst Matt Singh writes: “At no point in the past quarter of a century has the largest party’s seat total been wrong by more than 15 seats.”

We will be updating this story with more analysis of the key statistics and patterns from the election as they emerge.