Two things that everyone knows: poorer areas have lower voting turnouts than richer areas, and safer seats have lower turnouts than marginals.
I’ve looked at these effects in this general election: they both exist, but one is much bigger than the other. I used data on 2010 election turnout, 2005 election closeness and the April 2010 Jobseeker’s Allowance claimant count for each constituency in Britain.
The JSA numbers are hardly a perfect guide to unemployment, but they’re all I can find available on a constituency basis, and the result is striking:
The dots are mostly grouped pretty closely around a very clear line; the correlation between unemployment and turnout is -0.76. So some of those most affected by government policy are least likely to vote.
As for the safeness or marginality of a seat, here the correlation with turnout is still significant, but a much more modest -0.45:
There’s still a clear tendency, but the dots are mostly a lot farther from the line of best fit than they are in the unemployment chart. (The correlation between turnout and 2010 majority is a even feebler -0.13.)
So to all those electoral reformers who say that abolishing ultra-safe seats would boost turnout: on these figures, abolishing pockets of high unemployment would boost it even more. And it might even be a good thing in itself.