Polls are about to open in the UK General Election. 15 hours from now they will close and, instantly, broadcast networks will reveal the result of the “Exit Poll”. This is widely quoted as the clearest indication yet of the likely result, as it is an indication of how people who actually voted say they have voted, rather than how they intend to vote.
For the record, the Exit Poll consists of asking people to re-fill in the ballot paper, with the results then compared to outcomes at the same or similar locations previously. That gives the likely swing in marginal seats, and thus a clear clue as to the overall outcome. So, how have they done?
The first attempt at a proper exit poll was in 1970. Polls had consistently pointed to a likely Labour victory under Harold Wilson, as it defended a majority of 97 from the election four years previously. The exit poll was attempted by the BBC in only one constituency, Gravesend, which was regarded as the closest to typical in England. It produced a surprise, with a swing in fact suggesting a narrow but workable Conservative majority for Ted Heath. This proved astonishingly accurate – the actual result was a Conservative majority of 30.
A similar attempt was made in February 1974, and suggested something close to a dead heat. So it more or less was – despite winning most votes, the Conservatives fell 21 seats short of a majority and four behind Labour, meaning Harold Wilson took over in Number 10 but knowing he would soon have to test the pollsters again.
In October, the replay occurred. This time, a Harris “on-the-day survey”, supposedly wider ranging than previously, suggested a whopping Labour majority of 130. This was at odds with ITN’s effort, which suggested a wafer-thin Labour win. Interestingly, the bookies took the BBC’s words for it and were soon all but rejecting bets on an outright Labour majority. Embarrassment awaited, however, as early results showed just a narrow swing to Labour, whose final majority of just three was far closer to ITN’s call and caused a major inquiry at the BBC.
In 1979, with Labour’s Jim Callaghan already having lost a Vote of Confidence and thus lacking a majority, the BBC did not risk being too specific about whether Margaret Thatcher’s Conservatives were likely to take over. However, the median projection just after 10pm was a Conservative majority of 12. This had once again underestimated the Conservative vote, but not as badly as five years previously as the UK’s first female Prime Minister in fact earned a majority of 44.
In 1983, there was still some wariness about overplaying the on-the-day survey (broadcasters waited a while after 10pm to promote the result), but in fact the BBC suggested a Conservative majority of 146 with their opponents (Labour under Michael Foot and the SDP-Liberal Alliance under David Owen and David Steel) split. That was almost exactly what happened – the final outcome was 144.
Spurred by the effective triumph of the survey four years previously, in 1987 the BBC gave much more detail about its on-the-day work. Those details, it said, suggested Neil Kinnock’s Labour had made significant gains leaving a sharply reduced Conservative majority of 26. There was some concern, however, that ITN had a rather different outcome of 68. As in the second election thirteen years previously, it soon became apparent that ITN was nearer the truth and the BBC swiftly increased its projection towards the actual majority of 102. Another inquiry followed.
1992 was the first year in which broadcasters did an actual exit poll as it is now understood. This was announced exactly as Big Ben chimed 10pm. Contrary to commonly stated myth, the exit poll in fact did suggest the Conservatives (now under John Major) were the largest party, but short of an overall majority. ITN and newcomers Sky did their own polls which more or less agreed. As so often in the past, they had in fact understated Conservative support, as Mr Major was given an overall majority of 21.
In 1997 at 10pm a bruised BBC said nothing other than it was a Labour landslide under Tony Blair. ITN was in fact more specific, suggesting a Labour majority of 159. The BBC exit poll was in fact quite a long way out, considerably overstating Labour support by four points; but since a landslide is a landslide, few noticed as Mr Blair romped home 179 ahead of all other parties combined.
The 2001 election was almost a repeat of 1997 but in this case the BBC did give a figure at 10pm of a majority of 161. William Hague’s Conservatives had probably in fact lost seats, it suggested. In fact, they hadn’t (overall), but the error referred to LibDem marginals not to Labour ones – Mr Blair did indeed have a majority of 163.
By 2005, all networks used the same exit poll. This was now a hugely detailed effort at great expense, and that work appeared to have paid off – at 10pm it suggested Tony Blair had a third term with an overall majority of 66. In fact, this time it had overstated the fortunes of Michael Howard’s Conservatives against Charles Kennedy’s Liberal Democrats, missing the scale of the latter’s jump to 62 seats and consequently overstating Conservative fortunes. Nevertheless, the majority was now bang on at 66.
In 2010, after Cleggmania, the BBC’s surprise was obvious as it suggested the Conservatives under David Cameron were the largest party but short by 19 while the LibDems under Nick Clegg himself had in fact lost ground despite the campaign struggles of Labour PM Gordon Brown. In fact, it had if anything slightly overstated the LibDem total, but the fundamental figure for the lead party was again exactly right.
2015 was widely seen as exit polls’ finest hour, yet in fact it was the worst exit poll since 1997. The BBC declared only “Conservatives Largest Party” without quite specifying a hung parliament, before suggesting that they were short by just ten, having gained ground. Ed Miliband’s Labour had been left behind after 41 losses to the SNP and scant consequent gains in England, it suggested. This was deemed a huge success as it was so much closer to the actual result (a Conservative overall majority of 12 including the Speaker) than any pre-election polls. Nevertheless, it bears repeating it was in fact much further out than any other this century.
Where will you be at 10pm this evening…?!