Voice Referendum Polling Accuracy

The 2023 Voice referendum was a triumph for Australian (and in one case UK) opinion polling.  With all votes counted apart from a few dozen that may or may not exist, here is my assessment of the accuracy of the final polls, and of the polling overall.  

Before I start a few words about the late count: firstly the Yes vote rebounded after the first night of counting from projecting to the low 39s to finishing up at very nearly 40 (39.94 pending any late corrections, which would appear unlikely at this stage).  The main causes of this were: a strong performance by Yes on absents, a relatively strong performance on out-of-division prepolls (which were intermediate between absents and in-division prepolls) and both these forms of votes being substantially more common than in 2022 (29% and 22% more common respectively).  The latter also pushed the turnout up from the initial mid-to-high 80s range to more or less 90%, with it finishing at 89.92% (up 0.1% on the 2022 Reps election, but also up over 400,000 voters because of increased enrolment).   That said because it is harder to get one's vote rejected over enrolment issues, a better comparison might be the 2022 Senate turnout of 90.47%, on which turnout was slightly down.  

34 divisions voted Yes, including all in doubt after the night except for No's closest victory in Hotham, and 117 voted No.  Tasmania pipped NSW for second highest state Yes vote by 0.02%.

The polls overall

The Voice referendum was among the most heavily polled electoral events in Australian history, and the single most diversely polled with at least 22 different pollsters releasing some kind of result on the Voice since the 2022 federal election.  The polling was characterised by a refreshing lack of herding and saw a range of approaches taken in terms of headline figures (these could be broken broadly into one-pass, two-pass and forced choice approaches).  The major national polls towards the end were in general exclusively online, the main variation being that DemosAU used device engagement whereas the others employed panel polling.  This lack of method diversity turned out not to be a problem.  

Voice Referendum Polling: Rolling Final Week Roundup

Two-answer aggregated estimate (FINAL) Yes trails 41.3-58.7
No projected ahead in every state, but significant doubt about Tasmania

Unweighted two-answer average of all final polls Yes trails 41.8-58.2

Introduction (9 October)

Welcome to my final week's thread for rolling coverage of Voice referendum polling.  There may be a further polling post on Friday, or not, depending on time and the volume of material.  There may also be side posts on any matters of special polling interest and perhaps even at some point a big rant about why we are here.  The previous edition was here and click on the "voice referendum" tab to view all previous instalments.  

This thread will be updated in the sections below.  The two main graphs will appear at the top and be updated from time to time.  Significant polls will appear in the Major Polls section, scrolling to the top. 

As an overall summary of the state of play, the Yes vote for the Voice referendum may have been declining as early as August 2022 (based on two polls at that time) and was certainly declining by December 2022.  Since then Yes has lost just over 20 points of polled support, falling from the low 60s to the low 40s.  This may seem extreme, but in fact some other referendums have lost more support faster, including the 1988 referendums and the 1951 Communist Party ban referendum.  

People are already voting in significant numbers.  Any late swing back to Yes in polling (as has appeared to a statistically non-significant degree in the most recent Resolve and Essential) is not remotely likely to carry it to victory and the only way Yes now wins is if there is a catastrophic polling failure, several times the size of what happened in 2019  As the polls are quite widely spread in their estimates, that seems even less likely.