Swing-a-nomics

I made a bit of a flippant comment in my last post about the share of vote the LibDems would need to win the election outright. I was wondering hypothetically (that is I was wondering on a hypothetical subject…not hypothetically wondering) what swing the LibDems would need to get a majority in a hung parliament and further to that – an outright win. It seems it’s not an easily answered question.

According to Sir Robert Worcester, Visiting Professor of Government at LSE (most distinguished…and he looks it too) they’d need a uniform swing of 7% to be the majority party on c.250 seats and just over 8% to reach the magic 326 seats to form a government.

This is a little odd as the Guardian swingometer doesn’t give them as winning the election at a 10% uniform swing. Perhaps the Guardian has got it wrong – it wouldn’t be the first time (I’ve said that before I think).

Also this analysis by international affairs columnist Renard Sexton on FiveThirtyEight.com seems to suggest the LibDems need a much bigger swing. Their top 42 target seats require a 0.35-9.9% swing. That means the further 150 seats they’d need to be the most ‘seated’ party in parliament need more than a 10% swing (let alone the further 75 seats to win the election).

Now, I’m no mathematician…but the figures seem to suggest that the LibDems would need a much greater swing than 8% to take power.

My head hurts and I think I'm going for a lie down.

Any ‘swingometicians’ out there? (And I’m not talking about experts in swapping partners!)