Voice Referendum: Turnout and Informal Votes

I haven't seen any other articles on these subjects so some coverage of turnout and informal votes in the Voice referendum.  

The most important thing to know about Voice turnout is that it was a lot higher than many people said it was going to be.  It indeed managed to just beat the 2022 House of Representatives turnout, but this is no great miracle alone given that the 2022 election was COVID-blighted.  What makes it more impressive was that it was acheived against the backdrop of an enrolment drive that made the roll more complete than ever before, putting more voters on the roll who had a relatively low chance of voting.  Another factor that makes the near-90% turnout commendable is that six years ago there was a mass voting type exercise that was voluntary, and there was some potential for confusion about whether voting in the referendum was required.

Just a disclaimer before I get much further: when I post graphs with low r-squared values (percentage of variation explained) I come across a few readers for whom a little knowledge of statistics is a dangerous thing and who will, sometimes irately, insist that anything below r-squared equals 0.3 or so is worthless.  In fact electoral statistics are very messy and even r-squared values of a few percent can be statistically significant if there are enough data points.  The important thing with such values is to be especially cautious about assuming causation since the causes of such patterns are often to be found elsewhere.  For instance, in the 1999 Republic referendum, seats with high Yes votes had low turnout, but that isn't because high support for Yes in an area caused people to not vote, it is mainly because inner city seats that tended naturally to vote Yes also have high numbers of transient young voters (who themselves would be likely to vote Yes if they voted at all).  

Losing The Republic Like It's 1999: The Polling

The current Voice referendum with its rapidly declining support has brought back memories of referendums past.  Surprisingly, given that it's our most recent referendum, there has been little information available about the polling trajectory of the 1999 Republic defeat.  The received wisdom is that support for the Republic started off very high and ended up low, as happened with several other referendums (especially the 1988 quadruple failure) and as is so far happening with the Voice.

It turns out to be not so simple.  The story of the 1999 Republic referendum polling is one where only the last few months of data are all that usable, and in public polls at least, Yes was never all that much in front.

A summary of Republic polling is available in one paper available online but I thought, surely there was more?  I could not find any usable online archive of Republic referendum polling but what I did find, to my surprise, was some polling commentary in an article I published in Togatus April 1999.  1999 model me - not then a polling analyst so please cut some slack for misusing "push-poll" for a seriously bad polling question - wrote this:

"Poll results are confusing. In the last week of January the Age/AC Nielsen showed a national 41% yes vote, but Newspoll showed 58%.[*] The latter was a virtual push-poll because it included the statement 'this will most likely mean that the head of state will not be a politician' and ARM won't get even that simple message through to a thick republican public that mistakes an extra election with people-power."

[* 59% actually. This Newspoll wording was said to have been sourced from the ARM, and was roundly and rightly condemned by opponents as out of step with other polling at the time.]

In fact, question wording was a major issue in 1999 polling, and a case where public polling itself influenced the ballot paper design for the better.