Below is the most pointless, meaningless and useless graph I’ve ever drawn in my life.
It plots the % No vote by electoral division on the vertical axis against the percentage of Indigenous residents in each electorate on the horizontal axis.
And by using Indigenous residents on the x-axis, I am overstating the number of Indigenous voters. I didn't get chance to extract the data for aged over 18, or deal with turnout issues, both of which reduce the percentage of Indigenous voters compared to residents.
On first drawing I included a trend line that came up with the ridiculous conclusion that the No vote would reach 100% when the Indigenous population reached 30% of the total. That's because most electorates have a tiny percentage of indigenous residents and there is a vast range of Yes/No results. Only 26 electorates have more than 5% Indigenous residents and only six have more than 10%. If you draw a trend line in this data, you are trying to explain a wide range of No% results against a much smaller range and low number for percentage Indigenous.
The only electorate with an indigenous population large enough to influence the outcome was Lingiari, which has a noticeably lower No%.
I keep hearing that "All electorates with an indigenous population above 5% voted No" as if this says something about indigenous voters. If Indigenous voters make up 5-10% of the population, how can it be responsible for a high No%?
If you argued that experience and proximity to Indigenous Australians influenced the voting patterns of the majority population who are not Indigenous you might be able to mount a case. But you can't draw a conclusion from electorate level data about how Indigenous electors voted because there are just not enough of them to explain the results.
On the chart, as you move from Franklin to Solomon to Kennedy, you get two five percentage point increases in the Indigenous population, but two 15 point increases in No%. If you make the ridiculous assumption that the extra Indigenous voters all voted No, that still leaves you trying to explain the other 10 percentage point increase in No%.
Drawing conclusions from the above chart is a classic case of incorrect statistical inference caused by 'ecological fallacy'. In comparing No% against Indigenous%, you are comparing properties of electorates with an enrolment of 120,000 with Indigenous population which in all but one electorate is under 18,000, and in over half of electorates is under 5,000.
Even if you get a strong relationship between these two variables, you can't automatically make inferences about how individual voters or sub-groups of voters behaved based on the aggregate properties of electorates.
And in this case we have almost no relationship between No% and Indigenous% so drawing conclusions about how Indigenous residents voted is frankly ludicrous.
If you drill down within electorates to voting patterns in communities with a high proportion of indigenous residents, you detect more information about how Indigenous voters in these communities voted. And the majority voted Yes. But even this is difficult to extrapolate to a broader Indigenous vote scattered in smaller proportions across the country.
So let's stop quoting No% figures for electorates with only 5% indigenous residents. The electorate results tell you nothing about how the small number of indigenous voters in those electorates voted.
PS - this is the sort of post that attracts cranky responses. I won't post such responses unless they have a real e-mail address. Go to Twitter if you want to be anonymous.
PPS - the views expressed in this post are entirely my own.