16 April 2010
Tory / Labour seats / votes stats since 1979
Right. Have sobered up and checked the figures over. Hopefully this is at least vaguely visible. If not, the red line is the percentage of seats won by Tories / Labour in general elections since 1979, the green line is percentage of popular vote.
Two things to note:
1) The big bloody gap between them. Thank you FPTP. Particularly the 1983 drop-off in the popular vote having little impact on the seats gained.
2) Both lines drop over time, and the trend lines look on the better side of parallel.
I have estimated a 1.25 uplift from votes to seats. Now, if the share of the popular vote drops to 65% (reasonable given the more recent trend) then the share of seats should drop to about 80%, leaving about 125 seats in the hands of 'other. If - if - the vote share drops further, to 60%, the share of the seats would be c.75% and there would be about 160 'others' in Parliament (there are 92 at the moment, the most ever).
Anyway. Stats not really my thing and I'm crap at spreadsheets, but this is what I was wittering about last night after the debate.