Does AV make some votes count more than others?

But, in many ways, your vote alone is not enough. In the days and weeks ahead, you also need to challenge your friends and colleagues who are thinking of voting “Yes”. Ask them why they are voting for it. I bet you none of their arguments will stack up – and you need to take them on.So when they say: “AV will make every vote count”, tell them it won’t. It will actually make some people’s votes -especially those who vote for extremist parties – get counted more than others. [David Cameron arguing against AV in the London Evening Standard].

Is the Prime Minister correct with this line of argument? I don’t believe so. A clue to the argument I’m about to advance that Cameron is incorrect lies in the fact that AV is also referred to Instant Runoff Voting.

In full (i.e. non instant) Runoff Voting, what happens is that if in the first round of voting, no candidate obtains a majority of the vote, the lowest placed candidate is eliminated and another round of voting occurs. This process repeats until a candidate obtains more than 50% of the vote.

AV/Instant Runoff Voting aims to approximate this process by replacing multiple rounds of voting with multiple rounds of counting. If you assume that voters who voted for a candidate in an earlier round will vote for the same candidate in later rounds unless that candidate is eliminated and that voters for eliminated candidates will redistribute votes according to their preferences, then by asking at the outset what those preferences are, and then performing multiple rounds of counting until a majority winner is found, you can eliminate the need for several rounds of voting but can still retain the essential point of Runoff Voting, namely trying to achieve majority support for the winner (admittedly the majority is only of those votes making it through to the final round).

Note that in full Runoff Voting, every voter gets a chance to vote in every round, and all votes count equally in each round of voting. By comparison, under AV, every voter gets a chance for their vote to count in each round (by stating their preferences should their preferred candidates get eliminated) and each vote counts equally in each round of counting, it’s just that some votes are first preference and some votes are later preferences, just as is the case under Runoff Voting.

Cameron’s argument implicitly ignores the fact that the votes obtained for a candidate on first preference in the first round get carried through to the next round unless and until that candidate is eliminated, which is the equivalent of voters sticking with the same candidate through multiple rounds in run-off voting. These votes are in fact counted once in each round just like every other vote is.

It thus seems to me that the argument Cameron advances is flawed, equivalent to claiming that full Runoff Voting makes the votes for the lowest placed candidates count more than higher placed candidates when it clearly doesn’t. Each round of voting/counting treats each vote equally under both systems.

The main thing missing from AV that you get in full Runoff Voting is actually the opportunity for voters to change their minds from round to round, i.e. vote for A in round one, but for B in round 2 despite A still being in the running. Runoff Voting thus allows voters to alter their preferences from round to round, but this opportunity is not available either in AV or FPTP, so is irrelevant to making a choice between AV and FPTP.

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Will Alternative Vote lead to more coalitions?

British Prime Minister David Cameron claims that Alternative Vote (AV) could lead to coalition governments becoming the norm in British politics:

But there’s another argument I want to make – and one, again, you might find surprising coming from a Prime Minister leading the first coalition government since the Second World War: we shouldn’t vote for a system that could make coalitions the norm rather than the exception.

Cameron’s recent speech also claimed that AV would make coalition government much more likely:

The more people see a clear link between the pledges in a manifesto and the action taken in government, the greater the sense of accountability.

And the real, unavoidable truth about AV is that it would damage that chain of accountability…

…because it makes coalitions much, much more likely.

Furthermore, on Have I Got News For You this week, Tory MP Louise Bagshawe (about 16 mins in) claimed we’d end up with coalition governments under AV “every single time”.

The problem with this claim, is that the evidence for AV making coalition more likely than FPTP is inconclusive, but does suggest that a strong 2 party system makes coalition under AV unlikely, whilst under a multi-party system it will still tend to produce a majority for one party, even if coalitions occur more often in such cases. For example,  according to Channel 4’s Fact Check blog:

  • Australia has been using AV since 1919 and, according to the IPPR, has only had 2 coalition governments since then (compared to 5 for Britain since 1900, and 12 for Canada since 1900 under FPTP). However it should be noted that this comparison is complicated by the fact that the Australian National Party and Australian Liberal Party have for decades fought general elections under a coalition agreement both in and out of power, but this agreement has operated to such an extent that they’re effectively treated as one party for general elections. If you treat them as 2 separate parties, then they had coalition governments from 1949 to 1972, plus after the 1980, 1998, 2001 and 2010 elections. Whilst this amounts to a sizeable period of coalition government, it’s not the norm, not as much as you’d get with PR, and certainly isn’t a coalition “every single time”. Also, it’s not clear whether FPTP would have led to fewer coalitions under circumstances where you have a multi-party system with 2 parties having such an entrenched agreement — they could equally have had a pact not to oppose each other in constituencies where this would “split the vote”.  It does suggest that coalitions and even long-running cross-party agreements may become quite common under AV when voters move decisively away from voting for one of two big parties, but then consider how often Britain had national governments and cross-party agreements in the 1920s and 1930s when the Liberals were split and in decline but Labour had yet to decisively supplant them — that was all under FPTP.
  • The British Election Survey(BES) has run simulations of how British general elections would have turned out under AV since 1983, assuming voters preferences were the same as they were at each election. Only in 2010 does a coalition government definitely result (and we know FPTP delivered one then), though possibly we might have had one in 1992.

Of course assessing the likely outcome of switch to AV is inherently speculative, e.g.  the BES assumes voters preferences would be unchanged under AV, whilst Australia has a different political culture to that of Britain and the form of AV used there is different to that proposed for Britain making extrapolation from their experience rather uncertain.

It’s worth noting though that much speculation that we’ll end up with hung parliaments rests on the idea that the Lib Dems will benefit by being the second preference of both Labour and Tory voters, however given their rapid drop in the polls since forming the coalition with the Tories in 2010, that does not seem a safe bet anymore. Furthermore, under the projections of the BES, where the Lib Dems were often a second preference,  the Lib Dems did gain more seats but coalition rarely resulted partly because, in the simulation, AV actually increased the government’s majority in landslide elections such as that of 1987, 1997 and 2001.

In the end, given that AV will not produce a proportional outcome, and can result in amplified majorities in landslide elections in a similar manner to the way FPTP does, it seems to me that it is unlikely to make coalition government the norm, but it is possible it’ll make coalition occur more often if voters continue to vote in sizeable numbers for parties other than the 2 main parties. It’s hard to say whether FPTP would avoid coalition in such circumstances.