Predictions for the General Election

This article first appeared in the Daily Telegraph online on 7 May 2015

The election will be close, but not impossible to predict

In the year of the two hundredth anniversary of Waterloo both the main party leaders may ruefully recall the words of the Duke of Wellington: "It has been a damned nice thing - the nearest run thing you ever saw in your life." For May 2015 is likely to be the nicest (closest) election for many years.

The actual result is in the hands of the voters, but one can predict the shape of the likely result. These predictions are based on independent work conducted by Electoral Calculus, as well as other predictors, using published opinion polls and betting market prices. Of course, the polls have been wrong before, notably in 1992 when a Neil Kinnock victory was wrongly predicted. So nothing is certain, and probably some of these predictions will not turn out true. That said, here are the top ten predictions for the general election result.

(All predictions are ninety per cent likely unless otherwise stated.)

Parliament Will be Hung

The Conservatives and Labour are approximately equal in the polls at around thirty-three per cent each. Both need a lead of about five per cent to have an overall majority in the Commons, and this now looks pretty unlikely. So with a high probability, no party will have an overall majority.

The Conservatives Will be the Largest Party

Although close, the Conservatives have a small lead over Labour in both the polls and the betting markets. In terms of seats, the Conservatives might be around 5-20 seats ahead of Labour. This prediction is slightly less certain, with a 75 per cent chance of coming true.

Labour plus SNP Gets More Seats Than Conservatives plus Lib Dems

In a hung parliament, what matters is the number of seats that different blocs of parties can put together. The two main blocs will be the existing coalition parties and the left-of-centre grouping of Labour plus the SNP. Although Ed Miliband has downplayed a formal coalition or deal with the SNP, there is still likely to be some sort of arrangement or understanding if that would enable a minority Labour government. Much will depend on whether this left-leaning bloc is larger than the existing coalition. It probably will be, but only with a 60 per cent chance.

The Liberal Democrats Will Lose Most of Their Seats

The voters seem to hate Nick and Clegg the Liberal Democrats for taking part in the coalition government. Lib Dem support has dropped from 24 pc to around 10 pc. Consequently, most Lib Dem seats will be lost, usually to the benefit of Labour. The Lib Dems might end up with no more than twenty seats, according to the Electoral Calculus model, but the incumbency factor might help them keep a further ten.

The SNP Win Most Seats in Scotland

Since the referendum last September, the SNP have jumped to a commanding lead in the Scottish opinion polls, currently averaging 49 per cent. They would then replace Scottish Labour as the dominant political force in Scotland. They will win over half of the 59 Scottish seats, and might well win around 50 seats.

UKIP Wins No More than Five Seats

Although UKIP will win over ten per cent of the popular vote, or over three million votes, these votes will achieve little. The electoral system is not kind to third parties with evenly-spread support and UKIP will win Clacton, (possibly) Thanet South, and maybe a couple of others. But the main effect of these UKIP votes will be to transfer twenty seats from the Conservatives to Labour.

Evens Chance of Labour/SNP Having Majority

Although the bloc of Labour plus SNP is likely to be the largest grouping in Parliament, it is a toss-up whether they will have the 326 seats necessary to guarantee a majority. If they do, the majority will probably be slender, and it is just as likely to be a minority grouping. Labour would then require co-operation not only from the SNP, but also from other minor parties.

Greens Win One Seat

Caroline Lucas will retain the Greens' seat in Brighton Pavilion, but the Greens will not win any other seats. Their one and a half million youthful voters will be confused and upset.

Lib Dems Almost Wiped Out in Scotland

The Lib Dems might hold on to Orkney and Shetland, but they have collapsed in Scotland to only 5 pc support and will lose nearly all their seats. Some high-profile names, including Danny Alexander and Charles Kennedy, will fall victim.

The Next Prime Minister Will Be... Hard To Predict

Even knowing the exact parliamentary result doesn't help predict who will emerge as Prime Minister from the inter-party negotiations that will follow. The bookies have the odds finely balanced between David Cameron and Ed Miliband at fifty-fifty. Even after polling day, it may still be the nearest run thing you ever saw.

Post-election: How did the predictions work out?

There was a large amount of poll error at the 2015 election. On average the national opinion polls had an error of six per cent, which is nearly as large as the memorable 1992 polling fiasco. This error inevitably fed into many of the predictions and invalidated them.

But in the spirit of scientific inquiry, here is a post-mortem of which predictions were right and which were wrong.

  1. Hung parliament. This was the key prediction, and it was absolutely wrong because of the polling error. In reality the Conservatives won a twelve-seat majority in the Commons.
  2. Conservatives are largest party. This turned out true.
  3. Labour/SNP larger than Con/Lib. This also turned out absolutely wrong because of the polling error.
  4. Lib Dems lose most of their seats. This was completely correct, and they won even less than the minimal figure of twenty mentioned in the prediction.
  5. SNP win most of Scotland. Scottish polling was reasonably accurate and this prediction came famously true.
  6. UKIP wins no more than five seats. UKIP poll numbers were fairly accurate and the Electoral Calculus model accurately translated that into a single seat, as mentioned in the text. This is exactly what UKIP won.
  7. Evens chance of Labour/SNP majority. That certainly didn't happen, and given the right polling numbers its chance would have been much smaller than fifty-fifty.
  8. Greens win one seat. This was completely correct.
  9. Lib Dems almost wiped out in Scotland. This was completely correct. The only seat they held was Orkney and Shetland, as suggested. The others were all lost.
  10. The next PM is fifty-fifty. Again this was sabotaged by the polling error. Knowing that the Conservatives were 6% ahead in public opinion would give David Cameron a much higher chance of being Prime Minister.

So overall six out of ten predictions came true. But the four which failed were all major predictions describing the overall outcome. So those were serious failures. And the failures all had the same cause, which was the polling error in the published opinion polls.

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