Following some of the recent comments about the use of the Single Transferable Vote system for the C&RT Council elections, I decided to go off and give myself a refresher course in order to try and demystify it and, hopefully, lay to rest a myth or two. I won't try and explain how it works, because there is a really good explanation on Wikipedia here, which, it has to be said, puts the Electoral Reform Society's website to shame.
The first myth that needs challenging is that under STV you only get one vote, whereas under FPTP (first past the post) you get as many votes as there are seats. In fact, under STV, you get to express as many preferences as you like, up to the total number of candidates. What's more, you can differentiate subtly between them, whereas under FPTP you have to pick four (if the C&RT elections were held on this basis) as if you liked them all equally, and reject all the others.
Under STV, it's true, your votes don't all count equally; your first preference carries more weight than your second preference, and so on down your list, but overall, that gives a result that more closely reflects the wishes of the electorate, and your own preferences too. And of course, under FPTP, it is perfectly possible that none of your votes will count at all, whereas under STV you can be certain that they all have weight.
Take an example in which there are ten candidates for four seats, and a total of 10,000 votes are cast. Under FPTP, you vote for Albert, Bill, Charlotte and Denise, but Gus, Henrietta, Ignatious and Jane are elected. Your four votes have all been completely wasted; you might as well not have bothered filling in the ballot paper. Furthermore, say Jane needed 800 votes to get elected (don't forget that under FPTP, especially if there is a large field of candidates, it is perfectly possible, indeed likely, that people will win a seat on the basis of a very small share of the vote), but she actually got 3000. That means that 2,200 of those votes were also wasted; they didn't count.
Under STV however, if you vote for a candidate who is eliminated because they have too few first preference votes to be elected, then your second preference vote will be counted, and so on. Likewise, if your first preference candidate is elected with votes to spare, your second preference will be counted and so on. The way in which surplus votes are redistributed varies, but with computerised counting systems it is now possible to redistribute surplus votes in proportion to the second (or subsequent) preferences expressed in all the votes counted, not just a random selection of ballot papers.
STV encourages positive voting, voting for the candidates you want to win; it makes negative and tactical voting not only difficult, but unnecessary. It militates against party (or other group) domination and is fairer to individual and independent candidates.
It is not a purely proportional system, although in a party based election, where constituencies are large enough, it will produce a reasonably proportional result, and certainly more so than FPTP, but that isn't its only, or even its primary advantage. It is its fairness between candidates, and the accuracy with which it reflects the electorate's wishes, that makes STV the best system for the C&RT Council elections.