The Crazification Factor

John from Kung Fu Monkey discusses the General and Special Theory of Crazification: in any population of voters, you have to assume a base 27% of Crazification Factor, people who vote based on no rational basis whatsoever.

I recall seeing statistics that show that, in any survey, no matter how simple, at least 10% of people will give nonsense answers. [Source needed.] Ask any large enough group of ordinary people "Is water wet?" and one in ten people will say No, because they don't understand the question, because they accidently ticked the wrong box, because they are compulsive liars, because the voices in their head tell them to, or just because they can. This suggests strongly that there is a significant element of irrationality in human behaviour.

Daniel from Crooked Timber describes the voting patterns in the 2003 UK local elections, and independently reaches that same figure of 27% nutters (or at least, single-minded individuals who see things ... differently).

The Crazification Factor makes a good argument in favour of compulsory voting: whatever percentage of eligible voters actually bother to vote, 27 percentage points of them are nutters. In the 2003 UK elections, voter turnout was 36%. This means the weirdos outnumbered the non-crazies by 27 to 9, or about 3:1. But with compulsory voting, the Crazification Factor remains about the same, while the non-crazies increase: say, 27 to 73.

Perhaps that's why Australia, with compulsory voting, doesn't seem to be plagued by quite as much irrationality in politics as the US or UK.