Growing up in Northern Ireland has the advantage of having three easily accessable political arenas: Northern Ireland, the Republic of Ireland and the UK. So mentally hopping across borders and discussing what's going on in each area becomes almost second nature - perhaps this is why I warm so easily to the EU. The UK is preparing for a referendum on changing the voting system from First Past the Post (FPTP) to the Alternative Vote (AV).
Living in Northern Ireland,* I could vote in local, NI and Wesminster elections** which were held using the Single Transferable Vote (the same system is used for the elections in the Republic), but FPTP for Westminster elections. It's a very strange feeling going from STV elections to FPTP ones, and the abiding feeling was one of a loss of choice and power as a voter. In the Republic, attempts by the Fianna Fáil party to change the electoral system from STV to FPTP failed - the electorate saw it as an attempt to rig the system in their favour and to reduce the power of the voter. As STV is AV with more MPs per constituency, when there can only be one winner - in by-elections or for the Presidency in the Republic - AV is used.
So it's very hard to understand the political reactions of the British media (and people?) to the political changes over the last year. Coalitions? Preferential voting? "The sky is falling in!" the media seemed to cry. Today in the Guardian there's a poll saying that support for AV has fallen to 33%, with those against at 44%. It's difficult to explain how strange this seems for someone who has voted according to preference in the vast majority of the elections he's been involved in - particularly the claim that AV is complicated and voters won't understand it. Perhaps this is an Irish/STV thing?
While a system of proportional system would be better, I support AV for the following main reasons:
1. It empowers voters and shakes up safe seats. By being able to vote according to preference, suddenly the first preference doesn't have to be tactical anymore. Preferences can be expressed according to the candidate according to his/her personal ability and/or party affliation, and this means that candidates will have to represent the views of the constituency more faithfully as party membership will be less able to grant near-automatic victories in safe seats. This will encourage voter turnout. Though tactical voting will remain with the lower preferences (there's no electoral system that can eliminate tactical voting), it will free up first preferences, and many safe seats may turn out not to be as safe as once thought once voters can express their first preference free of tactical voting.
2. It enables (though doesn't guarantee - that depends on the electorate) a greater degree of control over the political parties. Parties in the UK are very broad churches - almost coalitions - and their success seems to be based on striking a balance between different wings in such a way as to appeal to the floating voters in marginal seats. By encouraging candidates to appeal to the political sentiments of their constituency more directly, gradual change can be introduced into the parties. A right-wing conservative may be sitting in a seat that would prefer a more liberal conservative, but there is little way of influencing the outcome if they absolutely do not want a Labour MP, and so vote tactically. It should be stressed that this depends on the electorate making use of the possibility, and that it would be a very gradual and indirect way of influencing the balance within parties, but it should mean that parties are a bit closer to their constituencies.
Those are the main reasons for supporting the system itself (I'm not going to be exhaustive in explaining them, or this long post will become far too long), but there are wider cultural perceptions that are attached to AV and proportional representation systems which mean that British voters are (or seem to be) against changing from FPTP.
Chief among these reasons is the fear of coalitions. Coalitions won't automatically come from AV: it cannot change the party political system so radically that there will be great fragmentation. However, coalitions aren't a bad thing that necessarily mean that voters' choices are reduced. Parties are coalitions that are hard in themselves to influence, and where there are only 2 (or 2 1/2) choices for government, it's hard to determine whether, when these parties win an election, their programmes get a near-total endorsement. What's more, the decreasing vote for the main parties means that a majority can be won on about between 36-38% (the upper reaches of which are harder to achieve nowadays) - should a single party be given such power when they don't have the support of 50% of the people? Through coalitions there is a greater chance for the voters to strengthen one party or the other and shape their relative strengths.
Again, perhaps this is a cultural perception, as in Ireland single party government is a threat - at the last election (in February), it looked like there may be enough Fine Gael support for single party government, and the electorate switched votes away from FG to ensure that there would be a coalition (in Labour speak, a "balanced government"). Ironically the most unstable government we've ever had in the Republic was a FF single party government with a large majority. Still, the ability to give preferences for candidates across parties in STV enables voters to shape the representation of the constituency and the political balance in the Dáil for coalition building. The "dream team" approach to building a government!
AV is a very moderate change to the electoral system. It won't change things radically, it's still possible (and fairly likely) to produce single party governments, and it doesn't create a proportional repersentive system. Such a moderate change won't have the hyped-up affects on British politics that the Yes campaign suggest, but it will give constituencies greater control over their MP. And that's why it's worth voting for.
* Annoyingly, if not surprisingly, the parties in NI have split along Nationalist-Unionist lines on the AV issue, though none are advocating a return to FPTP for NI...
**I'm currently living in the Netherlands, and was annoyingly too late for a postal vote.