“Richard Di Natale is no Einstein” Nick Cater opines in The Australian, meaning … oh, we’ll get to that bat-fart crazy bit later. In the meantime, in his review of the Batman byelection, Cater has got his psephology and his maths horribly, horribly wrong. A minor matter of itself, it shows how the right mishandles science, to their own ends:

The party may be divided and its ambitions may have been thwarted in the byelection in Batman, but in inner-city silos close to major universities its support is, if anything, increasing.

The changing pattern of the Greens vote — strengthening within walking distance of an ­artisanal bakery zone, weakening elsewhere — was apparent at the Batman byelection …

Cater then goes on to cite the swings to Labor and Greens, absent the Liberals, of first preferences in a couple of representative booths:

In Westgarth, for example, the Greens vote jumped from 51% to 56%, while Labor recovered barely half of the swing against it in 2016.

Labor’s Ged Kearney won the election in the … suburbs farther from the CBD.

In Reservoir East, for example, Labor’s vote jumped from 35% to 51%. Yet it was the cannibalisation of the Liberal vote — 24% in 2016 — that gave Labor the edge.

The theory being that the inner/outer vote gap widened for both parties, in different directions. Trouble is, it didn’t. The Greens had large swings to them in the outer suburbs; simply not enough to combat the inherent majority of Labor there and the two-party preferred (2PP) swing to Labor in the “inner-city silos”.

The vote gap narrowed, not widened. To establish this, you need to do what Nick didn’t bother to do, which is assess the ratios between inner and outer booth swings.

So, let’s take Cater’s example of Westgarth, the “inner”-most booth in Batman, and compare it with Kingsbury, an outer booth.

In 2016, the Greens got 55% first preferences (FP) in Westgarth and 65% 2PP. In Kingsbury, they got 17% FP, and 30% 2PP.

In 2018, the Greens got 58% FP in Westgarth and 61% 2PP. In Kingsbury, they got 28% FP, and 35% 2PP.

So the way to measure whether the Greens inner and outer vote is diverging, as Cater suggests, or narrowing, is to make a ratio of those paired figures. Put 2016 Kingsbury FP over 2016 Westgarth FP (17%/55%) and you get a ratio of 0.309. Put 2018 Kingsbury FP over 2018 Westgarth FP (28%/58%) and you get 0.4827.

The 2PP ratio shows a smaller leap — 2016’s is 0.46 (30/65) and 2018’s is 0.58 (35/61) — but a leap nevertheless.

The larger the increase (towards 1 — absolute evenness) the greater the inner/outer Greens vote ratio has evened out.

Cater is simply wrong.

You can do this for just about any pair of inner and outer booths in Batman and get the same result (there’s a couple of anomalies), so how did Cater mess it up (aside from doing sociology at Exeter university)? Well he didn’t compare like-for-like. It doesn’t matter what the other party did, it’s what your own did, that measures the evenness.

Cater’s determination to shoehorn the results into his theory means he’s missing the big-shift. Knowledge-class Greens voters (and others, such as students and migrants) have been pushed into the middle and outer suburbs, such as Reservoir*. The whole demographic process is changing completely.

As I say, minor of itself, but it shows how the right-wing mind handles science — as a genre of wish-fulfilment. Not sure if the Einstein reference serves you well here, Nick.

Best, also, not to criticise Greens as cosmopolitan, distanced people “short on empathy, rich on compassion” when you’re talking about people like Bhathal and her family, who have run free medical clinics in the suburb they’ve lived in for decades; especially when you are, as Cater is, a mathematically challenged carpetbagger. You don’t need to be a genius to see that.

*quick, someone at the Menzies Centre ask Cater to say the suburb name “Reservoir”! Hilarity will ensue.