Analysis of informal voting - 2013 House of Representatives elections

Updated: 23 March 2016

If you are having difficulty accessing the PDF, please contact us for an alternate version.

Executive summary

Following each general election for the House of Representatives, the Australian Electoral Commission (AEC) undertakes an Informal Ballot Paper Study (IBPS) to analyse the levels and types of informal voting. Research based on the IBPS is fundamental to the AEC’s role in supporting electoral integrity by:

  • Informing education and information strategies to reduce informal voting, including through the provision of robust information at the polling place level.
  • Providing an evidence base for reforms to the electoral system, for example, by enabling analysis of:
    • the impact of Optional Preferential Voting
    • aligning savings provisions between the House of Representatives and the Senate.

The national informality rate at the 2013 House of Representatives elections (5.91 per cent) is the highest recorded since 1984 (6.34 per cent). At the state and territory level, the highest informality rates were in New South Wales, the Northern Territory and Western Australia, while the lowest informality rates were in the Australian Capital Territory, Tasmania and South Australia.

Figure 1. House of Representatives informality rates by state and territory, 2010 to 2013
House of Representatives informality rates  by state and territory, 2010 to 2013

Source: AEC 2013

The ten divisions with the highest rates of informal voting at the 2013 House of Representatives elections were Watson, Fowler, Blaxland, Chifley, Werriwa, Barton, McMahon, Parramatta, Greenway and Banks. All of these divisions are within Sydney, and are areas with consistently high levels of informal voting.

More than a third of all informal ballots cast at the 2013 House of Representatives elections were informal due to incomplete numbering, while about one in five informal ballot papers were totally blank, one in seven had non-sequential numbering, and one in ten had ticks and crosses.

Further, under new definitions of assumed unintentional and assumed intentional informality, more than half of all informal ballot papers at the 2013 House of Representatives elections were assumed to be unintentionally informal. About six in ten of these had incomplete numbering, one in five had non-sequential numbering and one in seven had ticks and crosses. About half of all ballot papers assumed to be intentionally informal were totally blank, while a little over a third being informal due to having scribbles, slogans or other protest vote marks.

Table 1. Informal ballot papers by category, 2013 House of Representatives elections: Australia
Category Clear first preference No clear first preference Total Proportion of all votes cast
no. no. no. % %
Totally blank .. 169 354 169 354 20.9 1.23
Incomplete numbering – number ‘1’ only 239 352 .. 239 352 29.5 1.74
Incomplete numbering – Other 55 274 .. 55 274 6.8 0.40
Ticks and crosses 75 140 9 561 84 701 10.4 0.62
Other symbols 4 137 2 767 6 904 0.9 0.05
Non-sequential numbering 91 276 25 356 116 632 14.4 0.85
Scribbles, slogans and other protest vote marks .. 117 564 117 564 14.5 0.86
Illegible numbering 3 817 2 571 6 388 0.8 0.05
Voter identified 210 .. 210 0.0 0.00
Other 6 087 8 677 14 764 1.8 0.11
Total 475 293 335 850 811 143 100.0 5.91

Source: 2013 Informal Ballot Paper Study.

Divisions with higher levels of informal voting tended to have consistently higher proportions of ballots assumed to be unintentionally informal, while divisions with lower levels of informal voting tended to have higher proportions of ballots assumed to be intentionally informal.

There are many factors that could cause a voter to intentionally or unintentionally cast an informal vote. In many cases, it is not possible to accurately quantify or even separately identify the impact these factors might have. The very nature of the secret ballot, as well as the uniqueness of the election environment for each federal election, means that it is not possible to conclusively determine why a voter may have voted informally. However there are a number of variables that appear to have a relationship with informal voting. The Australian Electoral Commission (AEC) has investigated a variety of factors, using both AEC and Australian Bureau of Statistics (ABS) data, and found that:

  • The change in the number of candidates between elections is a significant predictor of changes in informal voting.
  • Voter confusion about the differences between state and federal voting systems may influence the number of ballots with incomplete numbering or ticks and crosses in some states or territories.
  • Poor English proficiency continues to be associated with an increased propensity to vote informally.
  • There are a wide range of socio-demographic and socio-economic factors associated with geographic areas recording higher levels of informal voting. Many of these are consistent with the theory that people are more likely to cast an informal vote if they are socially excluded or disadvantaged in some way.

The sheer number and types of factors identified in the socio-demographic and socio-economic analysis (as well as the complex interrelationships between these factors) emphasises that there is no ready or simple solution or set of strategies to reduce the numbers of informal votes cast. However this research will help the AEC in developing future strategies to address informal voting, to enfranchise more voters and heighten the integrity of elections.

Back to top