Watching the AV referendum debate on The Daily Politics (courtesy of afneil) the most striking thing that came up was the question of whether some individuals get more than one vote, or if their vote 'counts more' under AV than it would otherwise. The implication is borderline invidious and given that the entire debate over AV concerns how it would affect the individual voter (it certainly is not proportional), it deserves a prompt disection.
In first past the post the majority candidate wins, outright, simple as that. Everyone gets one vote, and these votes are tallied to find out who has the most. This often generates so-called 'safe seats' where one party has a substantial advantage, and voters for other parties may feel their vote will make no difference. Major parties may ignore these areas, as they don't expect to change the outcome. In all areas of the country minor parties, which have no chance of winning seats and therefore affecting policy are routinely regarded as a waste of votes. This is the main reason that proponents of AV claim that under the existing system not all votes are equally important.
In an AV system there are different 'rounds'. In the first round the first preferences are counted, just like in FPTP, and if one candidate gets more than 50% of the vote, they are elected. The difference emerges if no candidate is able to achieve a simple majority, in which case a second round begins where the candidate with the least votes is removed, and the votes cast for them are given to each voter's second choice. If a candidate now has more than 50% of the vote, they win, if not the process continues. This is called an automatic run-off system.
In any given round under AV every voter has just one vote. Those who voted for a candidate who was eliminated change their vote to their second preference automatically, all other voters vote for their first preference, as before. In the final count, where one candidate receives over 50%, every voter is still voting once, but those whose first choice candidate was eliminated are forced to vote for someone they like less-- potentially allowing them to help avoid the choice they like least.
This is a solution to the 'transitivity problem'-- that by voting for the party you like most, you may inadvertantly help the party you like least. For this reason many people vote 'tactically' under first past the post, instead of voting for a party they most agree with, but which has no real chance of winning, they vote for the 'realistic' candidate that they most like, or least dislike. This makes FPTP a 'lesser of two evils' system at times, and this is the main problem AV actually seeks to fix.
This would lead to more votes to minority parties, especially the more popular minorities, including the lib dems, but also the green party. Parties like the BNP would also most likely get more votes. This leads to the claim that under AV voters who select the most extreme parties would get multiple 'choices'.
Most people agree that it would be healthy to remove tactical voting from the equation, but many are concerned about additional votes going to extreme parties like the BNP. This is partially legitimate; there are feedbacks involved. If a party is able to get more first preference votes, because of the reduction in tactical voting, they may find it easier to maintain a power base and to continue to grow.
However, they would still have an enormous fight in order to ever actually get more than 50% of the vote, AV wouldn't give seats to the BNP.
Another concern expressed in today's debate is that those who vote for parties like the BNP get a disproportionate amount of influence. This is not strictly true, their vote is wasted under the current system as it has no chance of affecting the outcome either nationally or regionally in most cases, unless it draws support from the main parties. Their vote would be more likely to be counted, yes, although the same is true of many other minor parties-- including the liberal democrats, who often suffered from tactical voting.
AV would lead politicians to court more diverse constituencies, however, groups like the BNP are minor in this, and have had this effect under FPTP in any case-- the immigration cap introduced by the coalition has been attacked by virtually all policy experts, and was widely seen as a reaction to the increasing concern about immigration, and the fear it might manifest in support for extreme parties. The benefit is that politicians would mostly be courting mainstream voters-- after all, a tory would rather have the second preference of lib dems, of whom there are many, than of BNP voters, of whom there are few.
1) The first past the post system leaves us with a large number of 'safe' seats, seats where the party has a large enough majority that there is no serious electoral contest. AV would make these seats significant less safe by requiring candidates to get 50% of the vote to win.
2) AV would most likely not change the overall outcome of most elections, and might exagerate majorities. The main factor in the rise of coalition politics was an increase in the number of voters willing to go outside the main two parties, but AV affects results in both directions. (if labour and lib dem supporters were natural allies (this is in serious dispute currently) lib dems might help labour win elections via second preferences, and labour might equally help the lib dems, thereby helping the vote 'bloc' but not individual parties at the expense of each other)
3) AV would increase the number of votes cast for the smaller parties and decrease tactical voting.
4) Under AV voters who previously wasted their votes would have more influence on mainstream politics-- and this might exert a tug on the main political parties.
5) There might be an increase in voter participation if voters feel their vote is less likely to be wasted, and they have more choice.
6) Over a period of time smaller parties would find it easier to build up support, and this might-- or might not-- change the electoral landscape.
7) Under both FPTP and AV voters would be represented by a local MP, and this connection would exist whether or not they voted for them.
8) Protest votes are now less dangerous-- voters can register disenchantment with their first preference, by relegating them to second preference and voting for someone else, without the risk of helping to elect the party they least want.
If I'm missing anything really obvious out, and I bet I am, don't hesitate to eviscerate me.