Revised General Election Forecast gives Tories a Majority of 28

In the previous post I made a General Election Seat Forecast based on the massive YouGov regional opinion poll published on May 15. Based on a uniform swing in all seats in a region, this would have given the Conservatives a majority of 128. This was slightly below other forecasts, but still a substantial majority. In the past week, following the publishing of the Labour and Conservative Manifestos, the polls have swung substantially. The Sunday Times / YouGov weekly poll, published yesterday (21 May) gave Con 44 (-2), Lab 35 (+6), LD 9 (-2) and UKIP 3 (-3). YouGov today have published an opinion poll for Wales, giving Con 34 (-7), Lab 44 (+9), LD 6 (-1), Plaid Cymru 9 (-2)  and UKIP 5 (-1). All the changes are with respect to the regional opinion poll. These are quite large changes, by still leave the Conservatives with a nine point lead over Labour. Surely this will still leave a fairly comfortable majority? A recalculation on the same basis gives quite a startling result.

Figure 1 gives summarizes the General Election Result of two years ago.

The 330 seats gained by the Conservatives (plus 1 for the Speaker) gives a small majority in a 650 seat Parliament. As Sinn Fein never take their seats, this gave a small majority of 14. This with 37.7% of the vote (excluding Northern Ireland). Surely with 44%, the Conservatives should do significantly better? Figure 2 gives my recalculations, based on the latest opinion polls.

Conservatives (including the Speaker) see an increase of just 7 seats for 7% more of the popular vote. Labour see an increase of 2 seats for 5% more of the popular vote. The Conservative majority doubles to 28 seats. Figure 3 shows where the parties gain seats.

Very few seats change at all change under this forecast. Four regions see no seat changes at all. In three regions the Conservatives lose seats to Labour, and in London they lose two seats to the Lib Dems. The increased majority is reliant on the gains from the SNP in Scotland. Stemming the tide of the Scots Nats (who in the last year have been a more effective opposition than Labour) might alone be worth calling a General Election. Whilst a small majority would severely weaken the Brexit negotiating stance, for Labour under Jeremy Corbyn to poll significantly better than Ed Miliband in 2005 and Gordon Brown in 2010, would mean that he could retain power. The Labour Party would still be condemned to being a weak opposition under Corbyn, and the hard left would be able to consolidate their power.

Now there are some points that will likely give Theresa May a larger majority on June 9th.

First, the forecast I made last week gave a lower Conservative majority than the more sophisticated forecasts. Uniform swing does not allow for local battles. The Tories have more enthusiasm compared to a deeply divided Labour Party.

Second, the Labour Manifesto was well received in parts, but the larger picture of financing was based on some fairly implausible assumptions. The Conservative manifesto was weak in parts but was mostly more of the same. As a result it seems Labour may have peaked, and the Conservatives are having a wobble.

Third, the Conservative election machine is far more formidable than the Labour one. Once they re-focus the debate on twin themes of leadership and Brexit, the Conservatives are the more likely to gain ground.

Fourth, the last minute scare tactics will work against Labour. Expect the last Conservative Party Political Broadcast to feature Jeremy Corbyn’s qualities and past associations. Conversely Labour’s usual “24 hours to save the NHS” tactic has already been anticipated.

Kevin Marshall

General Election Forecast based on Uniform Swing by Region

On May 15, YouGov produced a General Election opinion poll broken down by the eleven Regions of Great Britain. It seems impressive with 14395 GB Adults, plus 1040 London Adults, 1017 Scottish Adults and 1018 Welsh Adults. However, with fieldwork on 24 April to 05 May, it might be a little out of date. By combining this with the General Election Results by Constituency (available for the British Election Study) I have been able to produce a crude forecast for the General Election on June 8th.

The starting point in the General Election Results of May 2015, shown in Figure 1. Since then Con has gained 1 seat from Lab (Copeland), and lost a seat to LD (Richmond). The sole UKIP MP, Douglas Carswell, left the Party in March to become an Independent. These are ignored.

Note that the 18 Northern Ireland constituencies are not included. The 331 Con seats are against 326 for a majority in the House of Commons.

I made the following assumptions.

  1. Within each constituency, for each Party I have assumed the change in the vote is the difference between the regional share of the vote in 2015 and the opinion poll share from YouGov.
  2. If the constituency vote share in 2015 was less than the regional drop in vote share between 2015 and current opinion poll, then the vote is nil.
  3. A party may have a predicted vote despite not having a candidate. There are two instances where this is possible. First is that UKIP are not standing candidates in every constituency. Second is that the Progressive Alliance of Lib Dems, Greens, Labour and the SNP are standing down candidates to maximize the impact of the anti-Tory vote. Guido Fawkes’ summary of 16th May is here.

This simple model produces the forecast in Figure 2.

Implied Conservative majority is 128, up from 12 in the previous Parliament. The Lib-Dems also increase there number of seats, whilst SNP lose 9. UKIP’s “gain” is in Buckingham, the seat of the Speaker. This is due to a flaw in the crude model.

The Party gains by region are in Figure 3

Of note is that Labour do not gain a single seat, as YouGov estimate that their popularity has dropped in all but two regions. In the South East and the South West Labours’ presence is quite low. The SNP in Scotland lose seats to both the Conservatives and the Lib-Dems, but the loss of 9 seats is would still mean they have 47 of 59 seats.

These switches in seats are shown in detail in Figure 4.

My very crude forecast can be compared to the current forecast by Martin Baxtor at Electoral Calculus of Con 409, Lab 167, LD 7 & SNP 46. The Conservative majority is 168, 40 more than my own.

Another comparison is the mid-point of the spread betting at Sporting Index. This Con 399, Lab 159, LD 15.5, SNP 45.5. The implied Conservative majority is 148, bang in the middle of my own and Martin Baxters’.

In subsequent posts I intend to

  • Clear up the obvious errors.
  • Refining the forecast for Scotland based on the local election data of May 5th.
  • Look at the forecast for Wales, where I believe YouGov might be out of line with popular opinion.
  • Update in relation to more recent, but National, polling. For instance the recent strengthening of the Labour poll share and the fall in the UKIP share.

Kevin Marshall

 

Will Labour be kicked out by voters in the marginals?

Mike Smithson  of politicalbetting.com has posted the results of IPSOS-MORI analysis, which shows the swing to the Tories is greater in the LAB-CON marginals than in the country as a whole.

Unlike Smithson, I do not find this surprising. It is not due to an anti-Labour bias (though I confess, indeed proclaim this), but due to a simple analysis. There is considerable resentment of the current Labour government, that may surpass in the polls that of the Tories in the late nineties. That is, where they are able people will vote to get the government out. In a Tory or Lib Dem seat this will not matter. In a solid Labour seat, there is a de-motivating factor. But in a Labour marginal seat – and that can include seats with greater than 10% majorities, voting against the Labour candidate may help remove the government.

This is why I do not believe it when pundits say the Tories getting 40% of the vote against 30% for Labour will result in a hung parliament. We may not get a reverse of 2005, where Labour were on 35%, just 2% ahead of the Tories and still with a working majority. But the resentment factor is now mostly directed at Labour, and they will get punished accordingly, with the Tories being the principle beneficiaries.