On Thu, Jun 14, 2012 at 5:37 PM, Juho Laatu <juho4...@yahoo.co.uk> wrote: > On 14.6.2012, at 23.45, Michael Ossipoff wrote: > >> If the district's population is off by one person, >> that's nothing compared to the amount by which even the best PR system >> will put it off, when allocating seats to fixed districts. > > Could you give me an example (or a formula or some other exact definition on > what goes wrong). Do you compare adjustable districts to fixed districts or > single-member districts to multi-member districts?
I was comparing adjustable districts to fixed districts. It's obvious that, with adjustable districts, re-drawn after each census, so that each district contains a (nearly exactly) equal number of people, and has an equal number of seats (one in this country, though it could be any number that's the same in each district), the district representation per person will be equal in each district, as nearly as desired. It's equally obvious that fixed districts, to which PR allocates seats, can't approach that equality. The smaller the districts are, the more unequal their PR district representation per person will be. No one claims that PR gives exactly the same district representation per person, in each district. ...Or exactly the same party representation per person to each party. That's common knowledge. One seeks, therefore, the PR method that most closely approaches that goal. That's what Sainte-Lague is for. But, for exactly equal district represent ion per person, you'd need census-based re-districting, preferably by an automated un-gerrymanderable method. > Isn't it so that also if we combine some of the single-member districts into > one multi-member district, we tend to get at least as good representation > density, if we compare e.g. the sum of deviation from the ideal > representation density over all people? It's so, and it's also entirely irrelevant. As I said, we aren't terribly worried if one congressional district has 699,000 people, and another congressional district has 699,001 people. If you're bothered by that much difference in district representation per person, then don't you find it a little odd that you are ok with allocating seats to fixed districts by Largest-Remainder instead Sainte-Lague. Where is your passion for precision now? With Largest-Remainder, we're talking about some much bigger differences in district representation per person, especially among small districts. Mike Ossipoff ---- Election-Methods mailing list - see http://electorama.com/em for list info