There’s a pretty terrible piece on Lib Dem Voice that essentially argues that because FPTP is biased towards the winning party, the Labour Party does not enjoy an advantage courtesy from the current constituency boundaries. Which is nonsense. But the stats do lead to a graph that suggests a few interesting things. The “fairness ratio” is based on the assumption that if, say, the winning party averaged only 90,000 votes per seat won while the 2nd party required 100,000 seats per seat, then they received an unfair advantage of 90 / 100 = 0.9 fairness ratio.
A nice simple concept which deserves to be knocked around a bit. The graph below suggests two things to me:
- FPTP delivers an increasing advantage towards the stronger party, so that as they become more popular they require fewer and fewer seats compared to their opposition. This bias is reflected in the slope of the line.
- Labour has an additional advantage, which means that in the elections they win they get far larger majorities in relation to votes cast. Hence their consistently lower ratio than the Tories – not a single red dot gets within 10% of the lowest blue one, even when the 2005 election returned them a smaller majority than the Tories in 1983.
I’m biased, I’ll admit. I want FPTP to go, and I think Labour does have a boundary advantage that should be removed. So perhaps I’m reading that into the data. Still, my reaction does seem reasonably objective. Dr J Lee (a mysteriously anonymous name) seems to think that if there is FPTP bias, then there can be no boundary bias, which makes no sense whatsoever.
Incidentally, the 2010 results aren’t in the above because in addition posting here I’m commenting on the linked article, and I’m restricting myself to the same date range.