Short history of preferential voting

First published in the Australian on 9 December 2014.

Australians have had preferential voting for national elections since 1918, but it took almost half a century for some key concepts to be understood.

This is something I wrote in 2006 for an academic paper I never finished. This being a longish Sunday, I’ve slightly polished and updated it and plonked it here.

It’s about the history of preferential voting in single member electorates (aka AV) in Australia, and people’s understanding of it. Thinking in terms of a national two party preferred vote (which is not very applicable to UK’s three party system) didn’t really arrive until at least the 1960s.

I. History of Preferential Voting in Single Member Electorates

Preferential voting in single member electorates, using one ballot paper, is an Australian invention.

When the colonies started running elections in the 1840s–50s their starting point, as with most things, was how it was done ‘back home’—in England. For voting system this meant first past the post.

The pre-federation colony of Queensland introduced a voting system called ‘contingent voting’ in1892. It replicated the then (and now) French two-round system, but on the one piece of paper, on the one election day, rather than successive weeks or fortnights or months. From the point of view of the voter filling out his (only males voted in Australia in 1892) ballot paper, it was identical to what we today know as Optional Preferential Voting: for a vote to count, a first preference had to be indicated, and the numbering of any more squares was optional. However, in the counting it differed from today’s OPV in that there were only two ‘rounds’: if no candidate achieved over 50%, all but the top two candidates were eliminated at once and all their preferences distributed.

Contingent voting saved the added expense of an extra election. Queensland carried it on at state level until 1942, when it adopted first past the post. In 1962 it joined most of the rest of Australia in moving to compulsory preferential voting, and in 1992 joined New South Wales in adopting OPV.

At the national level, the first elections for the new federated nation, in 1901, were run by the colonies/states. Each ran its own portion, using its own rules and franchise. Federal parliament then appointed a conference of the states’ electoral administrators to make recommendations for electoral arrangements, which were to be the genesis, with substantial modification, of the first electoral act in 1902. The conference recommended Queensland’s contingent voting, but with compulsory numbering of every square (recommendation 29). The version promoted by the Barton government, through Senator Richard O’Connor, was what we would today call OPV (Jan 30 1902, page 9534) (The government also advocated proportional representation in the Senate); Australia instead got first past the post in the lower house (and the terrible ‘block vote’ in the senate).

The second Commonwealth Electoral Act, in 1918 however, contained compulsory preferential voting in both houses. The Hughes Nationalist government largely introduced it because the rise of the Country Party had threatened to split the conservative vote. In the House of Representatives it was first used at a by-election in the Victorian seat of Corangamite, and then at the full general elections in 1919.
(The CEA 1918 also introduced preferential voting for the senate, which was even worse than the block vote. In 1948 legislation introduced STV, proportional representation, for the senate.) The states adopted preferential voting for their lower houses. Today all but Tasmania, which went its own way early, have CPV or OPV (Queensland and New South Wales) )

II. History of our ‘Understanding’ of Preferential Voting in Single Member Electorates

Preferences and aggregate national two party preferred votes have therefore been with us since 1919. Our understanding of it is another story, and has evolved in part by necessity as support for the major parties has decreased and preferences become more important. It seems that from 1918 until the late 1960s, political strategists and other interested parties no doubt understood the workings of preferences in individual seats, but the concept of a national two party preferred vote did not exist. In part this was because of the limited use of opinion polls and, apart from the rise of Lang Labor in the 1930s and 1940s and the Democratic Labor Party from the 1950s onwards, the major parties enjoyed, between them, high levels of support, and so preferences were not so important as today.

The political scientist Malcolm Mackerras was central in the development of our understanding of the concept. His entry in the Oxford Concise Dictionary of Australian Politics gives a fine summary of events. According to Mackerras, “[t]he intellectual origins of the two-party preferred vote go back to 1949″, conceptually anticipated in a research note by Leicester Webb. In 1957 Joan Rydon, measuring electorate margins, devised what she called the “adjusted two party vote”.

A decade later Mackerras adapted David Butler’s ‘swingometer’ to Australian conditions, called it a pendulum, and the rest is history. Mackerras continues the story:

“The first serious attempt to adjust for the massive changes brought about by redistribution came in my first book, The 1968 Federal Redistribution. The data from that was then put into pendulum form in a newspaper article. … It should be noted, however, that the Rydon expression ‘adjusted two-party vote’ never caught on. By contrast my re-naming of it as the ‘two-party preferred vote’ did win immediate recognition essentially because it was combined with a pendulum and because observers instinctively understood what it meant.”

In an email Mackerras has told me that the first federal election his pendulum was used for was in 1972.

In 1984 the newly created Australian Electoral Commission (which replaced the Australian Electoral Office), headed by academic Colin Hughes, began calculating and publishing full two candidate preferred votes for every seat and two party preferred nationally. They went back to the previous federal election, in 1983, and counted them out to full exhaustion, and then did it for all elections starting with the next one in 1984. They also estimated them from 1949 to 1980 by assuming likely preference flows for minor parties and independents. Gradually, most state authorities followed suit.1 Since around the mid nineteen eighties political scientists and other political observers have recognised the importance of the concept.

To explain the importance of two party preferred over primary votes, I like to make two points. One is that in a seat where the two main contestants are Labor and Coalition, the candidate who gets the higher two party preferred vote wins the seat – always. It is embedded in the preferential electoral system.

Secondly, a simple conceptual explanation is that if, after an election, you took all the voting papers in the country and made of them two piles, one containing ballot papers where the Coalition is ranked ahead of the ALP, and the other vice versa2, this is the two party preferred vote. It doesn’t matter where on the ballot paper the ranking is, and so it might be seen as especially appropriate in an age of much discussion involving electors choosing between ‘the lesser of two evils’. Another clear explanation is to draw on the comparion of the French/Russian/Latin American two round system, alluded to with Queensland’s contingent voting, above.

The most casual observer of Australian politics today can tell you that Labor won the vote but not the election in 1998 and the Coalition did the same in 1990. In 1987 the Coalition won more primary votes than Labor, but fell behind after preferences; this election is never included in the list because consensus, correctly, looks predominately at two party preferred votes. However, contemporary accounts in 1954, 1961 and 1969 observed only that Labor won ‘the vote’, that is, the primary vote, and there was recognition (for the last two) that DLP preferences had made the differences. The concept of a national vote after preferences did not occur. From today’s post-Mackerras world, we can say that, despite DLP preferences, the ALP also won the two party preferred vote on those three occasions. (The 1987 election was the first at which the party leading on primary votes did not win the two party preferred vote; the second was in 2010. [Update: but see this comment and response below about 1954.]) At all elections swings are ‘lumpy’, and there really is no particular reason why the winner of the national two party preferred vote should necessarily win the most seats.

But two party preferred data is a much better indicator of a party’s competitiveness than primary support.