First of all, I must say that I am not British even through I could have the possibility to vote in a British election as a Canadian citizen.
However, I am following closely the AV referendum from the other side of the pond which will be in the same week as the Canadian federal election.
I believe however that it is not of my duty to say to people for which side to vote (for AV or the current system), but to give them reflexions, so they could make their own decision.
As a fact, I find that all electoral systems in the world must have a few particularities to succeed:
-First of all, they must easy to use for the common citizen who is voting
-Second of all, they must be representative of people living in a known jurisdiction
-Third of all, they must give the most stable form of government as possible
But again, the main thing is that AV is not that better to the current FPTP system in this matter, even through that people sometimes confuse the AV system (used in the lower house in Australia) with the STV system (used in Ireland) which is a whole different ballgame.
In fact, even through AV have some advantages especially to help block more extremist parties who are finishing first, the system does not gives a better deal than the current FPTP system even for the Lib Dems who are the main supporters of this system. Even with this, only electoral districts where the first candidate only have less than 50%+1 will matters with this system.
Why? Because in a way the AV system gives the worst of both words because it gives weight to smaller parties in the wrong way, and this not in a way which will help them enter in parliament even in a modest way. Instead, the AV system will help create more backroom deals on preferences and this to help different parties trade preferences based on electoral districts.
And even in a mathematical way, the number of ridings where this system really matters is somewhat small, and this could even worsen the »safe seat » syndrome where only marginal or target seats are fought in a serious matter.
At the end, I am asking a question, why is voting compulsory in Australia? It is not the case in Canada, the US, France, Germany or New Zealand. Could this be more because of a specific political culture or more because of a lower turnout when the new system was introduced a few years ago?