I’m no expert on British politics, so maybe I’m actually the confused one. Anyway . . .
John Lanchester writes in the London Review of Books:
Labour have an enormous statistical advantage going into the election. The simple way of putting this is to say that votes in the country are worth less than votes in the city. That’s because the Boundary Commission has struggled to keep up with the historic drift of Britons out of cities into the country . . . Country constituencies are bigger, in population as well as geographical terms, than urban ones . . . Because Labour’s support skews urban and the Conservatives’ skews rural, this translates into a big advantage for Labour. How big? Well, this non-partisan article from the House of Commons magazine, dating from 2006 when the election was a long way off, reckoned that the Tories needed to win the election by a margin of 10 per cent in order to have any majority at all.
If you follow the link, though, it appears that (a) the boundaries were redrawn in 2005 or 2006, so the boundaries are only 4 or 5 years out of date, and (b) the “10 percent majority” thing is not coming from any imbalances in district sizes:
The Conservatives will still need a swing of about 10 per cent to win power outright . . . A swing of just over one per cent will now cost Labour its overall majority, compared to 1.8 per cent with boundaries unchanged. The changes reduce the swing needed by David Cameron to secure an overall majority from 11 per cent under the old boundaries to nine or 10 per cent with the constituencies which will be used in the next general election . . .
Got that? The effect of redrawing the district lines is estimated to be something like 0.7% of the vote, not 10%. (I’m getting 0.7% by subtracting “just over one per cent” from “1.8 per cent.”) If the boundary change in 2005 or 2006 comes to the equivalent of 0.7% of the vote, then I’d expect any population shifts since then to account for less than 0.7% in partisan advantage.
Less than 0.7%. Not 10%.
The 10% is coming from the multiparty system, which has at times benefited the Labour party and at times benefited the Conservatives and doesn’t seem to have benefited the Liberal Democrats at all (yet).
Bill James has a dictum that the alternative to doing good statistics is not no statistics but bad statistics. People who choose not to take numbers seriously–that is, as numbers–do not simply ignore numbers; rather, they treat them as words. In baseball, that meant, for example, going gaga over free-swingers who hit .300 in a hitter’s park and underrating low-average power hitters who draw walks. (Or, at least, that’s how things used to be before James and others popularized on-base percentage, slugging average, and all the rest.)
In the political context, Lanchester is pulling out numbers without regard to their magnitude–1%, 10%, what’s the difference? He wants to understand the political system–I respect that–but he doesn’t know where to start, so he picks out numbers where he can. I don’t think he’s trying to mislead, I just think this is what happens when you take numbers as words.
P.S. I happened to notice this one because I followed the link from Helen DeWitt’s blog. More generally, though, I notice a fair amount of innumeracy in the London Review of Books and (back when I used to subscribe to it) the New York Review of Books. For example, here, here, here, and here (from Gary Wills, Frederick Crews, David Runciman, and Samantha Power).
These people are all busy writers, and I can hardly expect them to find the time to think quantitatively, so I think a statistical copy editor would be a good idea. I think they could hire Ubs to do this for a reasonable fee, for example.
P.P.S. Yes, I know, hitting .300 in the majors is no mean feat. There’s no way I could hit .003 in any park. You could put me at bat every day for the rest of my life against anybody–major league, minor league, whatever–and I’d never even come close to getting a hit. The point above, though, is about comparisons of world-class athletes, which we can attempt even if we are leagues and leagues below them in ability.