How people elect parliaments
A looming redistribution of parliamentary seats between the Australian states has demonstrated that small changes have large consequences, with the national Opposition Labor Party set to yield a net four-seat gain for the next election over the current Coalition Government, which holds just a two-seat parliamentary majority.
The allocation of around 150 seats in Australia’s national House of Representatives among the states and territories is constitutionally automated by a mathematical formula based on population.
The seat allocation rule is applied exactly 12 months after each House election. The House has a maximum term of three years, but Australian governments can – and often do– call elections earlier.
Australian law also requires that the internal boundaries of the electoral divisions allotted to each of the six states and two territories are reviewed at least every seven years.
In practice this means intra-state electoral division boundaries can last for at most three elections, but usually last for only two. In some cases a set of state boundaries have been used for only a single electoral cycle.
In the United States and Canada redistributions (or ‘redistricting’) are carried out after each decennial census. This means US House of Representative seat boundaries normally last for five two-year terms, while Canadian House of Commons boundaries usually stand for three elections with House terms of up to four years’ duration.
In Great Britain the current law nominally requires redistribution of House of Commons constituency boundaries every eight years, but the only review cycle since this law was adopted is now running years behind schedule.
Redistributions in Australia, Britain and Canada are carried out by independent commissions using objective demographic and geographic criteria.
In the United States, however, electoral district boundaries are drawn by state legislatures, making most redistricting exercises highly partisan affairs. Many US congressional and state legislative boundaries are also seriously gerrymandered under the partisan system.
The Australian cyclical re-allotment of seats, announced today by the Australian Electoral Commission, will see the state of Victoria gain one seat (rising from 37 seats to 38), while the state of South Australia loses one seat (11 down to 10).
In addition the Australian Capital Territory will have a significant change, rising from 2 seats to 3 after strong relative population growth in the capital city, Canberra.
The total size of the House will therefore rise from 150 seats to 151.
The ACT electoral divisions will go from the nation’s two largest in terms of resident population to being among its three lowest, giving ACT residents an exaggerated higher influence on electing MPs, instead of a the low influence they currently have.
Even though the new maps will be drawn independently, analysts can foresee that all three changes will benefit the Opposition Labor Party.
In Victoria the areas of strongest population growth are in the north-western suburbs of the state capital, Melbourne. These are very safe Labor-voting areas, and the most probable effect of the new maps is an additional safe-Labor-voting division. It remains possible that the ripple effects on the boundaries of other divisions may moderate that political impact.
In South Australia, the divisions with the lowest populations are in the Liberal-voting rural areas. The impact of redrawing the boundaries will likely see either a rural seat, or a Liberal-held outer-suburban seat, abolished. This in turn would trigger a scramble for preselection in the remaining divisions by the sitting Liberal members.
The ACT is a solidly Labor-voting jurisdiction, so the creation of a third division there is also almost certainly a bonus seat for Labor.
Worst still, if the Government should call an early election before the redistribution work is completed in about 9 months’ time, the electoral law’s emergency rules would immediately apply to alter the boundaries of just two adjoining divisions with the largest (for a state with an increased allotment of seats) or smallest (for a state losing a seat) resident populations. On current population data, such abrupt boundary changes would certainly be applied in the Labor-voting north-west of Melbourne and in rural South Australia, making the already likely political impact virtually certain.
The current Australian Government has a 2-seat majority in the present 150-member House, with 76 seats to the Opposition’s 69, and 5 crossbench MPs.
While the revised boundaries will not apply until after the next election – which is not due until mid-late 2019 – the Government would nominally go into that election defending just 74 of 151 seats to the opposition’s 72.
Taking the divisions where the 5 current crossbench MPs are elected to be unaffected, this means the Government would need to actually gain seats to continue holding a majority in the House.
Australian House of Representatives seat boundary reviews are conducted by independent review panels overseen by the Australian Electoral Commission.
With scheduled 7-year redistributions already underway in the states of Tasmania and Queensland, a total of 5 of the 8 Australian jurisdictions – covering over half of all House electoral divisions – will see their boundaries changed in advance of the next federal election.
Gains and losses on the electorate roundabout (Christopher Giuliano, Australian Parliamentary Library, June 2017)