The opinion polls have obscured the view of what’s happening in the election rather than clarifying it. But bettors remain convinced of the following:
- The Conservatives are going to do better than most of the polling would suggest on an application of uniform national swing. The under/over line is set with Ladbrokes at 360.5, while the recent Opinium poll (which is fairly mainstream) would imply 349 seats.
- Labour are going to do worse than most of the polling would suggest on an application of uniform national swing. The under/over line is set with Ladbrokes at 209.5, while the recent Opinium poll would imply 221 seats.
- The Lib Dems, like the Conservatives, are going to do better than most of the polling would suggest on an application of uniform national swing. The under/over line is set with all the bookies at 10.5, while the recent Opinium poll would imply just 3 seats..
The problem is that these three assumptions aren’t really consistent with each other and past electoral history. Since the foundation of the Lib Dems, their seat count numbers have risen or fallen in tandem with their swing from or to the Conservatives. There have been years, such as 1997, when the Lib Dems’ poll share has fallen and they have gained seats. There have been years, such as 2010, when the Lib Dems’ poll share has risen and they have lost seats. But there has never been a general election where the Lib Dems have gained seats with a relative swing from them to the Conservatives (or lost seats with a relative swing to them from the Conservatives).
This is not particularly surprising, although it is at odds with the Lib Dems’ image as doughty campaigners whose performance is independent of their national vote share. The Lib Dems have primarily positioned themselves as the rivals to the Conservatives in seats where the Labour party is not in contention. Their battles with Labour have been much more localised. So you would expect the Lib Dems’ fortunes to be closely linked with their relative performance against the Conservatives rather than by reference to their absolute vote share. And so it proves.
Such rules are made to be broken. Over many elections, the Conservatives’ and the SNP’s seat tallies were on a similar seesaw, with the SNP never gaining seats in a year when the Conservatives gained seats and never losing seats in a year when the Conservatives fell back. But in 2015, after the independence referendum, the two decoupled, each leveraging support off the back of the other’s expected success.
Is the inverse relationship between the Conservatives and the Lib Dems likely to end in 2017? It doesn’t look likely to me. The Conservatives have put on support relative to 2015 in every single poll in the election campaign. Even those showing lower Conservative leads over Labour show them somewhere around the 43% mark. Meanwhile, the Lib Dems are at best flatlining at 8% or so – their appeal to appalled Remainers has cut no ice with most voters.
The par swing from Lib Dems to the Conservatives therefore looks to be at least 3%. It could easily be higher if ICM or ComRes are to be believed. And if bettors are right that the Conservatives are going to perform still better than the polls suggest, it must surely be higher. There are no obvious reasons to presume that seats that the Lib Dems have a special interest in are going to differ particularly from the par. Five of the nine Lib Dem-held seats have a Conservative challenger in second place. None of these look particularly safe.
So do the Lib Dems have other sources of seats to compensate? Not against Labour, against whom they have also suffered an adverse swing and who will be eyeing two Lib Dem-held seats with interest (and the Lib Dems have in any case few realistic targets against Labour). Their only real hope of putting on seat numbers if the polling is anything like the eventual vote share is to resist as best they can the twin-pronged attacks from the Conservatives and Labour, hope to nick a seat or two against the head and to win seats on tactical voting in Scotland.
Candidly, that doesn’t sound particularly plausible to me. It sounds even less plausible if the Conservatives are outperforming the polls thanks to a realignment of the underlying party coalitions or to superior campaigning techniques, as the current betting implies.
If you don’t believe that the Lib Dems’ polling is going to improve much or that the Conservatives are going to slip much further, betting against the Lib Dems is marked. Rather than take the “under” side of the bet at the Lib Dems taking 10.5 seats at 5/6, back them getting under 10 seats on Betfair (currently at 3.8). If you’re nervous about them taking exactly 10 seats, also back that on Ladbrokes at 10/1 for combined odds with the under 10 seats bet of just worse than 2/1 (much better than that 5/6 bet).
Personally I’m not bothering with covering 10 seats. I’m not expecting the Lib Dems to get that many.