[extropy-chat] 2-party-system = 1-dimensional politics (was polls again)

[Anders Sandberg]

I don't think 1D politics is due to 2 party systems. I did a PCA analysis
of Swedish politics (a 7 party system with proportional representation)
and found that it was dominated by just a single principal component (see
diagram at http://www.eudoxa.se/politics/dimensioner.html, text
unfortunately in Swedish). This component was the block structure of the
ruling center-left alliance, and the much smaller subsequent components
may hold ideological differences but could as well just be particular
patterns of party alliances.

My basic setup was similar to this
http://www.ex-parrot.com/~chris/wwwitter/20040203-which_parliamentary_co-ordinate_are_you.html
analysis of British politics, which uses majority voting and has a pretty
strong tory-labour dimensionality. Here politics is also pretty 1D, but
along simple left-right lines.

Looking at co-sponsored bills in Sweden showed a far more complex network
between the parliamentarians: http://www.eudoxa.se/politics/motioner.html
When it comes to voting the policies have become 1D, but when they are
still ideas and ideology they are quite multidimensional.


-- 
Anders Sandberg,
Oxford Uehiro Centre for Practical Ethics
Philosophy Faculty of Oxford University