In Defence of Liberty

Driven by data; ridden with liberty.

An AV Referendum Retrospective

In 2011, the UK roundly rejected the Alternative Vote. (Edited: conservativeparty)

In 2011, the UK roundly rejected the Alternative Vote. (Edited: conservativeparty)

As part of the coalition agreement between the Conservatives and Liberal Democrats, they pledged to hold a referendum on introducing the Alternative Vote (AV) system to the House of Commons.

This method involves voters indicating the order of preference of their candidates, with votes redistributed when the losing candidate is knocked out in a round. The sequential removal of potential MPs continues until one candidate holds an absolute majority. AV is also called Instant Run-Off Voting.

With a 41% turnout, the plebiscite resulted in 67.9% rejecting AV. This meant retaining First-Past-The-Post (FPTP): the plurality system where only a single preference can be recorded. Under FPTP, the candidate with a relative majority of votes is elected. In June 2010, changing to AV held a healthy majority in YouGov polling, but was quickly overtaken.

The Alternative Vote was rejected across the country. (Source: BBC/Electoral Commission)

The Alternative Vote was rejected across the country. (Source: BBC/Electoral Commission)


The No2AV campaign had three focal points: complexity, costs and Clegg.

FPTP is incredibly blunt. Expressing a single preference allows no distinction between votes cast in fervent support and votes cast in tactical opposition. Vote-splitting is a recognised problem with First-Past-The-Post: two similar candidates share votes from similar voters, thereby allowing a third candidate to obtain a relative majority. In the theoretical terminology, FPTP violates the criterion of clone independence.

AV fails the monotonicity criterion: a candidate can lose an election by improving their preferences. Suppose there are 100 voters electing one of three candidates: Scarlett, Plum and White. All of Scarlett’s voters put Plum as their 2nd preference, all of Plum’s voters put White as their 2nd preference and all of White’s voters put Scarlett as their 2nd preference. In one scenario, Scarlett gets 40 first preferences, Plum obtains 32 and White has 28. Under the AV rules, White is eliminated, passing their votes onto Scarlett, who wins with 68 votes. Alternately, suppose Scarlett campaigned harder, convincing people on the doorstep. Scarlett now has 45 first preferences, by taking five votes from Plum. This new election leaves Plum on 27 votes, with White remaining on 28. Plum is eliminated, passing their ballots onto White, who wins with 55 votes. Those five voters harmed the candidate they supported.


This added complexity means it can be analysed whether the electorate’s lower preferences flow towards particular parties, suggesting coalitions in the event of a hung parliament. FPTP is ideal for a choice between only two candidates, where all voting systems are equivalent.

One of the No2AV billboards depicted a premature baby, and read:

She needs a new maternity unit, not an alternative voting system. Say NO to spending £250m on AV. Our country can’t afford it.

The figure of £250m “on AV” includes an estimated cost of £82m for holding the referendum itself, and £130m on purchasing electronic counting machines, This expenditure is hypothetical: ministers confirmed no plans to buy these machines, and Australian elections not using them. Also, the Electoral Commission concluded the referendum cost £75m. Even if the £250m figure were assumed, improved democratic processes may be considered a worthy trade-off.

(Video: No2AV)


The No2AV campaign portrayed the Manichean duplicate of Deputy Prime Minister Nick Clegg, supposedly elevated to presidential status by “AV gains”. According to Full Fact, a report from the Political Studies Association acknowledged: “By boosting the Liberal Democrats, however, AV does increase the likelihood of hung parliaments a little.”

Many of the No2AV leaflets focused on the Deputy Prime Minister. (Source: Conservative Home)

Many of the No2AV leaflets focused on the Deputy Prime Minister. (Source: Conservative Home)

Hung parliaments are caused by the fragmentation of duopolistic politics. Smaller parties are being elected to a greater number of seats, meaning the difference between the two dominant parties must be larger. The parliament becomes hung because the politics is hung: without a clear winner.

Counting More than Others

Other arguments require addressing. The No2AV campaign believed we should vote against AV because few countries use it. All good ideas were once untried.

Prime Minister David Cameron suggested AV meant “some votes count more than others”. This is a misconception – the votes are counted the same number of times; the preferences are shifted between rounds.

AV is also not “fairer”, as the term is typically used in voting reform: AV is preferential, not proportional.

AV doesn’t eliminate tactical voting: it merely makes tactical voting more exotic.

(Video: liarpoliticians)

It is true that AV is more complex than FPTP: just as an orchestra is more complex than a triangle. FPTP suited the green benches being filled with Tories and Whigs. An ineffectual Yes campaign was flattened by vociferous opposition. The debate was drawn away from the relative merits of two voting systems, and onto conjectured costs and the machinations of incumbent politicians.

I admit I was wrong to reject the minor improvement of AV.



This entry was posted on February 8, 2015 by in National Politics and tagged , , , , .
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