2020 Apportionment of Seats: Part 1 – Allocating to the States

(Update 3 July – the determination has been published confirming that Victoria will gain a seat and Western Australia and the Northern Territory lose seats. Details here.)

On 3 July, Australian Electoral Commissioner Tom Rogers will issue his determination on how many electorates will be contested and representatives elected for each state and territory at the next federal election.

As the numbers stand, it is expected that Victoria will gain a seat to 39 seats, and Western Australia will lose the 16th seat it gained in 2016. Most controversially, the Northern Territory will lose the second member it has elected since 2001.

This is the first of three posts on the subject of apportioning seats to states and territories under Australian constitutional and electoral law. This first post will look at the constitutional allocation of seats to states under Section 24 of the Constitution, how the current formula works, past attempts to change the formula, and how past High Court cases have interpreted the workings of Section 24.

A second post will look at how seats are allocated to territories and the different constitutional origins of territory representation.

The final post, for those who already know the background, will be devoted to possible changes to the apportionment formula, drawing on the extensive history of apportionment in the United States.

Section 24 of the Constitution and State Representation in the House of Representatives

Representatives and seats are apportioned or allocated to states according to a formula set out in Section 24 of the Constitution. The terms of the formula are duplicated in Part III of the Commonwealth Electoral Act and are related to Part IV of the Act dealing with redistributions. The provisions were contained in the Representation Act prior to 1983.

As will be discussed, parts of the formula in Section 24 can be altered by legislation. This was done with an amendment to the Representation Act in 1964, but the amendment was declared invalid by the High Court in McKellar’s case (1977).

Section 24 is set out below. The meaning of the bold text is explained below the extract.

Section 24

The House of Representatives shall be composed of members directly chosen by the people of the Commonwealth, and the number of such members shall be, as nearly as practicable, twice the number of the senators.

The number of members chosen in the several States shall be in proportion to the respective numbers of their people, and shall, until the Parliament otherwise provides, be determined, whenever necessary, in the following manner:

(i) a quota shall be ascertained by dividing the number of the people of the Commonwealth, as shown by the latest statistics of the Commonwealth, by twice the number of the senators;

(ii) the number of members to be chosen in each State shall be determined by dividing the number of the people of the State, as shown by the latest statistics of the Commonwealth, by the quota; and if on such division there is a remainder greater than one-half of the quota, one more member shall be chosen in the State.

But notwithstanding anything in this section, five members at least shall be chosen in each Original State

Notes on the text:

as nearly as practicable” – the five seat minimum for original states, and the half-quota rule in sub-par (i), make it difficult to fix the House at exactly twice the size of the Senate. The Constitution therefore required it to be only “as nearly as practicable”.

twice the number of the senators” -the High Court in McKellar’s case (1977) ruled that this clause means twice the number of state senators, that is excluding Territory Senators. The existence of territory senators therefore cannot effect the entitlement of a state to House seats. There are currently 72 state senators and four territory senators, so twice the number of senators is 144, and this value is used to calculate the quota. Any change to the size of the Senate therefore results in a change to the size of the House and a re-allocation of state and territory representation.

until the Parliament otherwise provides” – where this phrase appears in the Constitution, it means that the text that follows only applies until Parliament legislates a replacement. In Section 24, this means the text in sub-paragraph (ii) on dividing by the quota and allocating extra seats for half-quotas can be replaced by legislation for a different method. Past constitutional cases have made it very difficult to change sub-paragraph (i) on calculating the quota. Other parts of Section 24 cannot be overridden by legislation. The two-to-one nexus between the House and the Senate, the five member minimum per original state, and the allocation of seats to states being proportional, require a referendum to change.

number of the people of the Commonwealth” – the High Court ruled in Mackellar’s case (1977) that this clause means people of the states, and so excludes the population of territories. The population of the territories therefore cannot effect the entitlement of a state to seats. Allocation is also based on “people”, not “electors”. Seats are allocated to states based on population, though the Electoral Act then draws boundaries within each state based on electors.

latest statistics of the Commonwealth” – redistributions were originally done following each five yearly census. The High Court ruled in McKinlay’s case (1975) that more up to date statistics than the census must be used and the allocation of seats must be checked every term of parliament. The Electoral Act now specifies that the Electoral Commissioner must issue a certificate on representation twelve months and one day after the first sitting of each new Parliament after a Federal election.

Original State” – indicates that only original states are guaranteed five seats. The Constitution does not grant five seats to new states. Section 121 grants power to the Commonwealth Parliament to determine new state representation “as it thinks fit”.

Section 24 is a constitutional restriction on how seats are allocated to states, not territories. The method of determining territory representation is for Parliament to decide, and since the 1980s the Parliament has tried to use the Section 24 formula to determine territory representation. That approach had to be varied in 2003 to save the Northern Territory’s second seat, demonstrating that territory representation is for the parliament to decide.

(For more on Territory representation, see my second post on the 2020 apportionment.)

How the Current Formula Works – the 2017 Determination

To explain the current apportionment formula, the table below sets out the calculations used to allocate seats in the 2017 determination, published 31 August 2017. (Full details of the 2017 determination can be found on the AEC website.)

The determination was based on the population of the Commonwealth (that is the original states) being 23,729,561. Dividing by 144 (twice the state Senators) gave a quota of 164,788.61806.

Dividing the population of each state and territory by the quota gives a quotient

The quotient is then used to allocate seats as follows –

  1. The number of seats equal to the integer part of the quotient (that is the number to the left of the decimal point) is allocated to each state and territory.
  2. All states where the fractional part of quotient is greater than 0.5 are allocated an extra seat.
  3. For original states, if the rounding produces fewer than five seats, then  the minimum of five seats applies.

Another way to look at the allocation is to do step one and two in a single operation. Seats can be allocated based on “natural” rounding, rounded down to the lower bound if the fraction is less than 0.5, or rounded up to the upper bound if the fraction is greater than 0.5. The allocation is a “natural” rounding of the arithmetic mean of the lower and upper bounds, that is  (Lower Bound + Upper Bound) / 2.

(That the formula uses an arithmetic means becomes important for discussing alternative formulas to the one in Section 24. See the third post in this series on the 2020 apportionment – yet to be published)

Table 1 shows the 2017 calculation of quotients, seats allocated, as well as the change in seats allocated since the previous determination in 2014. There are explanatory notes below the table.

Table 1 –  The 2017 Representation Determination

Population Quotient Seats Change
NSW 7,797,791 47.31996 47 ..
VIC 6,244,227 37.89234 38 +1
QLD 4,883,739 29.63639 30 ..
WA 2,567,788 15.58231 16 ..
SA 1,716,966 10.41920 10 -1
TAS 519,050 3.14979 5 ..
ACT 408,562 2.47931 3 +1
NT 247,512 1.50200 2 ..
  • The quotients for Victoria, Queensland and Western Australia were rounded up to the upper bound, NSW and South Australia rounded down to the lower bound.
  • Compared the previous determination in 2014, Victoria gained a seat and South Australia lost a seat.
  • Tasmania was only entitled to three seats by the calculation, but the Constitution guarantees it five seats as an original state.
  • The population of the ACT includes Jervis Bay and Norfolk Island. The population of the Northern Territory includes Christmas Island and Cocos (Keeling) Island.
  • In population terms, the ACT fell short of a third seat with a quotient of 2.47931. As explained below, since 2003 a statistical error margin has been applied to territories in the determination. Twice the statistical standard error added 10,694 to the ACT total, lifting the ACT to a quotient of 2.54420 and entitlement to a third seat.
  • The NT was entitled to a second seat on population alone. It would have been lifted to 1.547 quotas on standard error if it had fallen short of two quotas.

An explanation in how the formulas are tweaked for allocation to the territories is included in my second post on the 2020 apportionment.

Estimates for the 2020 entitlement review were published by the Parliamentary Library in July 2019. These project WA to lose a seat, down from 16 to 15, and Victoria to gain a seat, rising from 38 to 39. The same paper projected the NT quotient to be 1.430 quotas. Even statistical error would not be enough to save the NT’s second seat. (Find the Parliamentary Library’s estimates at this link.)

Previous Changes to the State Seat Allocation Formula

Until a High Court decision in McKinley’s case (1975), representational reviews were conducted every five years after a census. The cancellation of census in both World Wars and during the Great Depression deferred several reviews.

In the 1961 determination, Western Australia’s quotient was 8.4703 and Queensland’s 17.4387. Both states were due to lose a seat. As the law stood at the time, determination of seats using the Section 24 formula was not the final step of the process. The representation numbers did not apply until new electoral boundaries passed through parliament.

When the Country Party threatened to vote with Labor to defeat the new boundaries, the Menzies government withdrew the redistribution proposal and the allocation of seats to states remained unchanged for the 1963 and 1966 elections.

The Representation Act was amended in 1964 to apply a different formula to that set out in Section 24 (ii). The calculation of quota and quotient remained the same, but all quotients were rounded up to the next whole number, an extra seat allocated to any state with a quotient fraction greater than zero.

If the 1964 rule were applied to the 2017 determination shown in Table 1, NSW with 47.32 quotas would have been allocated a 48th seat, and South Australia with 10.42 quotas would have retained its 11th seat. All five mainland states would have received an extra seat above the quotient integer value and there would have been two extra House seat.

The legislative enactment of Section 24 was examined by the High Court in McKinlay’s case (1975) and McKellar’s case (1977) and resulted in major changes to the apportionment process.

The Impact of the McKinlay case

In McKinlay’s case (1975), the High Court ruled that relying on the five yearly census to determine the apportionment of House seats did not qualify as “latest statistics of the Commonwealth”. The High Court ruled that apportionment should be checked in every term of parliament, and if the entitlement for a state changed, then the correct number of members must be elected for that state at the next election.

This required two changes to the apportionment process. The first was to set a time when the review of representation should be undertaken. The second was to legislate what would happen if a state’s entitlement had changed, but new electoral boundaries had not been drawn in time for the next election.

After some fine tuning, the current provisions of the Electoral Act specifies that a  determination of state and territory entitlements takes place twelve months and one day after the first sitting of each new parliament. The “latest statistics” has also been clarified, and the current procedure is that population statistics by state and territory are drawn from the Australian Bureau of Statistics publication 3101.0, Australian Demographic Statistics.

For the 2020 determination, the 3101.0 statistics for the the December 2019 quarter will be used as the most recent statistics. These are due for release on 16 June. The Australian Electoral Commissioner will then make his determination on 3 July.

Dealing with incomplete redistributions has produced two solutions. The Fraser government legislated that if a state’s entitlement changed but boundaries were not complete, then the correct number of members for that state would be elected at large.

The Hawke government replaced that provision with mini-redistributions. If an election is called and new electoral boundaries are not in place, the following procedure should be followed –

  • If a state or territory’s entitlement is increased by one, then the two adjacent seats with largest combined enrolment should be divided into three seats.
  • If a state or territory’s entitlement is decreased by one, then the two adjacent seats with the lowest combined enrolment should be merged into a single seat.

Thankfully the mini-redistribution procedure has never been required.

Prior to the 1970s, all states had been redistributed at the same time after a census. The McKinlay ruling meant that redistributions could take place in some states but not others.

A new set of redistribution procedures were implemented by the Hawke government in 1983 setting three grounds for initiating a redistribution.

  1. that a state’s entitlement to seats had changed
  2. that more than one third of seats in a state were malapportioned, that is outside the permitted variation from quota
  3. that seven years had passed since the last redistribution

No redistribution has ever been triggered by provision (2). The determination on 3 July will set redistributions going in Victoria and Western Australia under provision (1), but not in the Northern Territory where the two existing seats will simply be merged for the next election. There are no seven-year rule redistributions under provision (3) due in the life of the current parliament.

The Impact of the McKellar Case

McKellar’s case (1977) invalidated the 1964 Representation Act amendment and reverted the seat allocation formula back to the method set out in Section 24 of the Constitution.

It also clarified that the population of the Commonwealth was the population of the states, and that twice the number of senators was twice the number of state senators. This reading of Section 24 by McKellar’s case meant that territory population and representation could not effect the apportionment of representation between the states.

But the High Court’s ruling in McKellar did not mean that Parliament had no power to amend the formula in Section 24 (ii). What it ruled was that the formula in the Representation Act was not “as near as practicable” as the formula in Section 24. No evidence was offered that the Representation Act provision was more proportional than Section 24.

The judgment made reference to Article 1, Section 2 Clause 3 of the US Constitution that representation in the House of Representatives be allocated to states according to their respective population. It also referenced the various methods used in the USA to achieve this end.

But as Chief Justice Barwick noted, the US Constitution has no equivalent of Section 24’s numerical relationship between the size of the House and the Senate, the two-to-one nexus provision. As implemented in the United States, the size of the House of Representatives is for Congress to determine, the chosen allocation formula then used to apportion seats to states.

Justice Stephen noted that the two constitutional requirements related to Section 24 were

… first that the number of members of the House of Representatives ‘shall be, as nearly as practicable, twice the number of senators” and, secondly, the proportionality requirement, that “the members chosen in several States shall be in proportion to the respective numbers of their people”. Of these two requirements the latter is absolute in form while the former is in qualified terms.

Stephen then went on to explain how compared to the formula in Section 24, the method in the Representation Act was both less proportional and not as close as practicable to twice the size of the Senate. As he noted –

… it is one thing to require the concept of a perfect nexus between the numbers in the two chambers to give way to the extent necessary for the attainment of more perfect proportionality of representation; it is quite another to sacrifice both proportionality and nexus at one and the same time and to do so without promoting any purpose which has been accorded any constitutional recognition.

Stephen went on to note with reference to US literature that there were other methods for proportional allocation of seats to states, and that if one of those were used, the High Court might not strike down the method. But as he noted, that was not the position the Court was ruling on in relation to the Representation Act.

Justice Gibbs was less interested in ruling on proportionality and struck the legislation down based on “near as practicable”. He also ran through the history of several US apportionment  methods that had been either used or proposed by the time of Federation. The Australian constitution’s authors had been uncertain of the precise method of insuring proportionality and left it to Parliament to otherwise provide.

So Can Parliament Legislate a Different Apportionment Formula to Section 24?

My purpose in running through the Section 24 and the apportionment of seats to states has been to address two questions –

  1. Can a different formula be applied to the two Territories that would provide fairer representation to the territories than the constitutionally defined state formula that the parliament has chosen to apply?
  2. Can a method used in the territories also be applied to the states without running foul of the High Court?

I’ll address the first of these questions in the second of my 2020 Apportionment posts dealing with territory representation.

In part 3 I will go into greater detail on apportionment methods used in the United States.  I also discuss why the extensive debate on the correct apportionment has less relevance to the debate in Australia. I also apply different methods to Australian apportionments back to Federation and demonstrate how the proposed methods applied to the territories could also be applied to the states and be argued as being more proportional than the present method.

5 thoughts on “2020 Apportionment of Seats: Part 1 – Allocating to the States”

  1. Antony, does s24 preclude any form of proportional representation from being legislated?

    COMMENT: No, but proportionality would have to be within each state and the same method would have to be used in each state. They would also need to pay attention to Section 24’s point that members must be directly elected, a phrase that has some High Court case law behind it.

  2. Tom the first and best

    Was the at large election for when the redistributions of states with changed seat numbers majoritarian (like the old windscreen wiper Senate) or proportional?

    A majoritarian system being used in one of the larger states would have led to a very lopsided Parliament.

    A proportional system being used in one of the larger states would have meant quite a low quota, likely meaning more than one Democrat and maybe other parties.

    Either system being used in one of the larger states would have meant a massive ballot paper and high informal rate.

    COMMENT: Entirely from memory it was proportional but lacked detail. This was before the introduction of ticket voting. I really don’t have time to dig through 40 year-old versions of the Electoral Act to provide a more detailed answer.

  3. It does seem rather unfair that the MP for NT will have to represent 247k people whereas Tasmania which has a population 2.17 times the NTs gets 5 (because of the minimum number of MPs it gets) each representing 107k.

    The ACT gets 3 times the MPs of the NT despite only having a population. 1.78 times that of the NT

    NSW gets 47 MPs each serving 172k population but is only 32.87 times larger in population.

    And there could come a time (And absent constitutional and law changes) because of population changes where the ACT could have the same population as Tasmania yet still have fewer MPs

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