Here's why the Coalition favours optional preferential voting: it would devastate Labor
- Written by Benjamin Reilly, Professor, University of Western Australia
Could a change be afoot in the way Australians vote in federal elections?
The Coalition government may be eyeing a shift to optional preferential voting — as used in New South Wales — which allows voters to simply vote “1” or allocate only a partial list of preferences on their ballot, instead of a full ordering of preferences for every candidate.
The proposal was included in a series of potentially revolutionary changes to our electoral system that were quietly released by a parliamentary committee in December, when few people were paying attention.
The joint standing committee on electoral matters claimed a shift to optional preferential voting would help address rising rates of “informal voting” in NSW caused by the differences between the state and federal systems. The reason: a valid vote at the state level with less than a full list of preferences would be invalid if repeated at a federal election.
What the committee did not say is that based on current voting patterns, a shift to optional preferencing could also cement the Coalition in government.
As a follow-up to a newly published study, we have modelled how recent federal elections would have changed if an optional preferential system had been used. We found the results would have been devastating for Labor.
Read more: Parliamentary electoral committee floats bigger parliament, longer terms and no byelections
Labor supported by Greens preferences
The reason the Coalition would benefit from an optional preferential voting system is simple.
In recent decades, Labor’s primary vote has slumped in federal elections, but full preferential voting has kept its two-party preferred vote high.
This is because Labor benefits from consistent preference flows from parties to the left, in particular the Greens. Approximately 80% of Greens preferences at federal elections go to the ALP at present.
Ellen Smith/AAPA significant proportion of this preference flow is the result of Greens voters being forced to choose between Labor and the Coalition at some point – even in their final preference markings on the ballot – so their votes are valid.
Labor and the Greens oppose changing the current voting system, but the proposal from the joint standing committee reportedly has support from some Senate cross-benchers.
Read more: With One Nation on the march, a change to compulsory voting might backfire on Labor
How Labor would have fared under optional preferences
Data collected by the ABC’s election analyst, Antony Green, at the 2015 NSW election shows the rate of Greens preferences transferring to Labor declines precipitously from 82.7% under full preferential voting to just 37.4% under optional preferential voting.
In our study, we extrapolated how past election outcomes would have been affected if this was repeated nationally. We were conscious of the challenges that come with generalising in this way, and comparing one state’s data to the country as a whole.
We found that in most seats, switching to optional preferential voting would have partisan effects that are sharply skewed to the right.
This is best illustrated by looking at the seats Labor has won in recent elections by overtaking the Coalition after trailing on first preferences. These would be the seats most affected by a shift from full to optional preferential voting.
These “come-from-behind” victories would become much rarer under optional preferential voting. By our calculations, Labor would have won somewhere between five and eight fewer seats at each recent federal election, as the graph below shows.
Authors: Benjamin Reilly, Professor, University of Western Australia