Monday, 14 April 2014

The SNP's chances in 2015: the early constituency betting

In stark contrast to the Lib Dem constituencies, all of which have been priced up by one or more bookies, the Scottish constituency markets are still being created.  Most of the interest here is with the SNP's chances.  Will they be able to increase their seat count in what might yet be the final UK Parliament that Scotland participates in?  Their polling is currently running far ahead of 2010 levels.  Can they convert this into seats next year?
I set out here the 59 Scottish seats in order of the swing required for the SNP to take them (with the six SNP seats at the end of the table): 

Two things immediately stand out.  First, the SNP is fighting a battle on three fronts.  And secondly, the size of the swings required to make even limited progress is daunting.  In many of the more promising seats, the SNP would need to come from third or fourth.  Not only would they need to dislodge the incumbent, they would need to muscle past existing established challengers.
So how do the bookies rate the SNP's chances?  Well, here are the seats so far quoted listed by odds:

This list is very incomplete.  The SNP's number one target by swing, Ochil & South Perthshire, is not yet listed by any bookie.  But already we can see that the bookies don't particularly fancy the SNP's chances.  They're odds against in every seat listed so far that they don't yet hold.
The SNP are, however, thought to have relatively better chances in Lib Dem seats than in Labour seats.  They are rated as having a far better chance (5/1) of achieving a 15% swing to win North East Fife from fourth place than of winning Edinburgh South on a 13.5% swing from third place (33/1).

The swings required for substantial SNP success are heroic. To put their chances in context, a 10% swing to Labour would give them a landslide majority.  A 10% swing for the SNP would give it five seats.

But the SNP do seem to be performing quite a lot better in Westminster polling than they performed in 2010 (be sure to differentiate between Holyrood polling and Westminster polling). It is far from apparent that this swing is yet enough to justify the short odds on SNP seats that are being quoted so far.

Looming over everything else in Scotland is the independence referendum. How might this affect voting intentions in 2015? It seems inconceivable that such an important referendum result will not have a major impact. In particular, if there is a Yes vote, it seems likely that the SNP will get a major boost in the polls. Seats that looked out of reach may suddenly become winnable.

The consequence of all of this is that some of the longshot seats may make good proxies for a referendum victory for Yes at much better odds. The chances of a referendum success for the SNP seem to have been fully priced into the seats where they are more fully in contention. This means, paradoxically, that the SNP longshot bets in constituencies may well offer better value than the short priced bets in seats that they have much better hopes of taking. Whatever your view of the matter, I maintain that the SNP are considerably more likely to take Edinburgh North & Leith, for which they are rated a 50/1 shot, than Charlie Kennedy's seat, for which they are rated a 10/1 shot. 

1 comment:

Thaddeus said...

Interesting post. I concur that if Yes wins then the SNP north of the border and Conservatives south of it will get a significant boost.

Isn't there a risk that a Yes could lead to the Scottish part of the General Election being suspended, though? Otherwise there would be the risk of Scottish constituency MPs sitting on the government benches as the government negotiates the separation of Scotland.