I wrote: > > But if we are looking > >at a national parliament of, say, 120 members, it would be > undesirable > >to elect all 120 from a single national-district. The > principal reason > >is not one of practicality, but rather political consequence. > >Experience has shown that it is politically undesirable to give > >representation down to 1 in 120, as the example of the Israel Knesset > >shows. In countries using party list systems of PR with national > >aggregation of votes to determine the parties' shares of seats, it is > >common to apply an arbitrary threshold (typically 5%) specifically to > >exclude small parties. These thresholds are arbitrary (Why > 5%? Why not > >4% or 6%?); it would be more logical to accept the de facto > thresholds > >that come with districts - where the sizes of the districts have been > >determined for other, logical reasons. > > > >For this reason I would reject all "extensions" of STV-PR > that seek to > >add any aggregation of votes across districts with the aim of > >"improving" the PR.
James Green-Armytage asked: > What it it about the Israeli parliament which proves > that high district > magnitude is a mistake in general? Israel uses closed party list in one national district. This is the worst possible combination of all PR systems. Any group that can secure 1/120th of the national vote will get a seat in the Knesset. This give representation to very small groups which makes it possible for the extremes of the political spectrum to gain representation. The system does not encourage them to seek any accommodation with those of less extreme views. Allied to this is the effect WITHIN parties of the closed list. The candidates of a minority faction within a party may be included on the party's list to ensure that the faction's supporters vote for the party, but those candidates will be placed well down the closed list so that they have no chance of election. To overcome this, the faction splits off to form its own party, when its candidates will, of course, be at the top of its own list. If it can secure at least 1/120th of the national vote, it will get at least one of its candidates elected. This is what has happened over many years in Israel. The political consequences are there for all to see. Many small parties are represented in the Knesset, many with extreme views (ie extremely different from one another). Coalition building has been very difficult to the point of near impossibility at times. When a coalition government with a small majority wants to take a difficult decision on some of the very difficult issues that face all governments in that part of the world, one or more of the extreme parties threatens to bring down the coalition. This gives the extreme parties power greatly in excess of their support among the electorate. This makes government very difficult. It could even be considered a denial of democracy as these tiny minorities may be frustrating the wishes of the majority of electors. Certainly the voting system gives them no incentive to seek consensus on the way forward. > >The law of diminishing returns applies to representation in much the > >same way as it applies to many other things. As the number > of members > >per district rises, the proportion of voters NOT guaranteed > >representation falls off very rapidly at first and then progressively > >more slowly. (This applies to all systems of PR, not just STV-PR.) > What are your grounds for saying that there is a > diminishing return of > representativeness with greater district magnitude? I did not say this. The law of diminishing returns states that for each successive equal increment of input the successive increments of output become smaller. Of course, the total output increases as the total input increases, but the law of diminishing returns relates to the relative increments. In the case of district magnitude, if we increase the number of members from 3 to 4 (an increase of 1), the proportion of voters not guaranteed representation by STV-PR (Droop quota) falls from 25% to 20%, a decrease of 5. But if we increase the number of members from 10 to 11 (also an increase of 1), the proportion of unrepresented voters falls from 9% to 8%, a decrease of only 1. I have a graph that shows this extremely well, but have yet to find somewhere I can post it with public access. (I asked if there was a FILES archive on this List, but no one has replied.) > I agree that this might be the case if you just measure > whether someone > is represented by whether they get a seat for the party they > like best, > but I believe that voters' true preferences are more complex > than just a > choice of one party or another, and so I'd say that there is > always room > for representativeness to keep increasing at the same rate. Views about where to settle on the diminishing returns curve will differ, but the diminishing benefit of each successive increment in district magnitude should be taken into account in considering the trade-off with the other factors that pull in the opposite direction. > You have to consider that there might be some ideas or > groupings that are > very important to people, but are never concentrated enough to have a > tenth of voter preferences. But do real voters in real elections mark enough preferences for this to come through? See, for example, my tabulation from the Meath constituency in Dail 2002 election, posted on 9 July. > >There is also a trade-off between the proportionality of > representation > >and the localness of representation. These two factors pull > strongly in > >opposite directions so far as optimal district size is concerned. In > >some political cultures, real electors attach great importance to > >localness and so it cannot not be ignored. > I agree that this is a tradeoff. It seems to me the > most important > tradeoff by far. > Again, electing some candidates in smaller districts > and others in larger > districts that encompass the smaller districts is a method of > having it > both ways. They could either be part of the same legislative > chamber, or > they can form two separate chambers. If nobody wants this, then people > just have to decide on a middle-ground. Maybe they should use > Condorcet to > decide. : ) > Actually, the only way of meeting both of these desires > at once is to > have a legislature that is just bloody huge. I'm not > especially in favor > of that, but it is worth mentioning. I don't see that the legislature has to be large. Potential district magnitude MAY be one factor to consider when deciding the size, but it is certainly not the most important. I certainly see no grounds for suggesting that members elected from large districts should sit in one chamber of the legislature while those elected from the smaller districts should sit in a different chamber. First decide whether you want one chamber or two. If you have two, then decide the appropriate district magnitude for the election of each of the two chambers. As I've already indicated in earlier posts, I am prepared to accept great flexibility in district magnitude within any one legislature, provided there is a sound rational for the variation. I am also prepared to vary the numbers of electors per elected member, in addition to varying the numbers of members per district. I know this is greeted with horror by many "PR purists", but I live in the real world and know what real people want, at least here in Scotland. It is a compromise and those who are working for practical reform should be prepared to recognise that. <cut> I am not in a position to comment on your views of the political culture in the USA. What you said does, however, emphasise the importance of taking the political culture into account when considering which voting system will secure the "best" representation for the electors. James ---- Election-methods mailing list - see http://electorama.com/em for list info
