P.R. (3)

So - STV. Voting is the same as ATV in that you rank the candidates in order of preference. But we're now dealing with multi-member constituencies, so we need a different way of deciding who is elected. And the way it's done is to divide the number of votes cast by the number of seats to be filled, plus one. So if 100,000 votes are cast, and there are 3 MPs to be elected, we divide 100,000 by 4 (3 + 1) and come up with 25,000. We then add one to this number and this becomes the quota. Any candidate who receives 25,001 votes or more is elected. But if, as is most likely, we don't end up with three candidates reaching the quota of votes what then? And this is when it becomes a bit complicated! Unlike ATV where votes are redistributed from the bottom up, with STV they are - at least initially - redistributed from the top down. Suppose candidate A gets 40,001 votes. They are obviously elected, but they have got far more votes than they needed for that, so the 15,000 surplus votes they have got are redistributed to those voters' second choice candidates. But hang one - which 15,000 votes? The answer is that all candidate A's votes are redistributed but on the basis that they are now only worth a 15000/40001th (just under 0.4) of a vote each - I told you it gets complicated! If there are no surplus votes, then we proceed as with ATV by eliminating the candidate with the fewest votes and redistributing their votes on the basis of second preferences. Still with me? More to come...