Over the past few years, Croakey has published many articles about the health issues surrounding marriage equality (an example) and the damaging impacts of a plebiscite.
In one of these articles, Sydney epidemiologist Gideon Meyerowitz-Katz gave three public health reasons why the government should act urgently to enable marriage equality.
Following the most recent news about the much-contested plans for a postal plebiscite, he argues below that it is “one giant, $122 million cauldron of sampling bias waiting to boil over and scald us with its nonsense”.
Gideon Meyerowitz-Katz writes:
When it comes to marriage equality, Australia has a tumultuous history. I say tumultuous, because it sounds much better than admitting that we are trailing far behind most OECD nations in being decent human beings to the ~20,000 same-sex couples who call Australia home.
Ultimately, there shouldn’t be any debate over same-sex marriage. Whether you are religious, atheist, or uninterested in labels, as long as you care about treating your fellow citizens as people you should be for marriage equality. It really is that simple.
Sadly, the Liberal party has been debating for some time whether LGBT people count as human beings, because despite this being clear to the majority of the developed world, it is still a question that some people think appropriate to ask.
Depressing, I know.
In the lead-up to the last federal election, this confusion led to the Liberal party promising a national vote, or plebiscite, on the question of whether we should let couples of the same sex marry.
With huge community outrage at the monumental $180 million price-tag, as well as the horrifying impact that a plebiscite campaign is likely to have on the LGBT community, the measure has twice failed to pass in the Senate.
Enter the Postal Plebiscite (PP).
Not a plebiscite
The first thing to note is that a PP is, by definition, not a plebiscite. A plebiscite requires a vote of the entire population — given that the proposed postal vote is non-binding it is unlikely in the extreme that the entire population of Australia will weigh in.
But the real issue with the PP is both simpler and more devastating.
Basic science renders it entirely worthless.
Sampling bias is a term used in epidemiology that defines a type of error that creeps in to studies when the sample that you are looking at is not representative of the population. What this means is that you are looking at a small group of people in your study who only represent a small sub-group of society.
Let’s take an example. Say I wanted to know the number of train journeys the average Australian takes each week. To do this, I stood in Central station in Sydney and asked random passers-by to tell me how many trains they’d caught.
I’m obviously going to get a biased result: people who are already at the train station are more likely than the average Australian to catch trains. If I wanted a really representative sample, I’d need to get some rural and regional respondents, as well as some people in the city who exclusively drive cars when they commute.
In short, sampling bias is picking a group that doesn’t represent the population. You can correct for it — most good political polls do — but even so it introduces a level of uncertainty over whether your results are accurate if you extrapolate them to a population that is at all different from the people in your sample.
As you may have guessed, the PP is basically one giant, $122 million cauldron of sampling bias waiting to boil over and scald us with its nonsense.
So who is the sample that is going to vote in the PP?
We know that it will be skewed towards older people. As soon as voting becomes non-compulsory, fewer young people turn up to the polls. Other factors that affect who votes are wealth, education, and gender (women vote more).
In general, the sample that you get when you don’t make voting compulsory is old, rich and well-educated. By choosing a non-compulsory vote, you’ve cut out all of the most vulnerable people in society, because they are the ones least likely to be able to take the time to do it.
These are also the people most likely to vote “yes” to marriage equality. A large proportion of the LGBT community fits into the category of young, vulnerable people, and they are the least likely to be able to get their ballots back in time.
But wait, there’s more.
The government is also proposing a postal vote. This makes it even more tricky, as the people who are more likely to use the postal system are, you guessed it, old and rich. Poor young people often don’t have fixed addresses, or are unfamiliar with the postal system because we’ve had better ways of conducting elections for decades.
You couldn’t bias a sample more if you tried.
If this was a scientific study, it wouldn’t get past the first round of ethics applications. They’d tell you it was nonsense and that you were wasting everyone’s time and money.
And it’s going to cost 122 million dollars.
Choosing a PP to decide on whether to give basic human rights to our fellow citizens is simply bad science.
It is guaranteed to give you a result that is, at best, a reflection of the most conservative elements of society. At worst, the answer will be completely meaningless.
Or, in the words of Malcolm Turnbull:
The voluntary postal voting method … flies in the face of Australian democratic values.”
As it happens, a non-compulsory postal vote is one of the few ways pretty much guaranteed to give you a worthless result. Scientifically speaking, you’d have better luck calling a few thousand people randomly and correcting for selection bias.
Of course, we’ve been doing that for over a decade now. It turns out that representative polls have been in favour of marriage equality for quite some time.
This latest push for a postal vote is nothing more than the most unashamed homophobia.
If the Liberal party is so uninterested in science, never mind basic human decency, they should at least have the courage to tell the Australian people rather than wasting $122 million taxpayer dollars on a piece of pseudoscientific charlatanry.
And remember; stigma kills. The right-wing campaign is almost certain to inflame hatred at the LGBT community. In fact, it already has.
So a PP will not only be worthless, it will almost certainly result in the deaths of LGBT people around Australia as vulnerable people are told by their neighbours that they are not deserving of basic human rights.
A postal plebiscite is a waste of time. It is a waste of money. It will almost certainly kill people.
It’s time for the government to do their jobs, listen to the people, and legalise marriage equality.
Gideon Meyerowitz-Katz is an epidemiologist working in chronic disease in Sydney’s west, with a particular focus on diabetes. He writes a weekly blog on public health, policy, and translating complicated health problems from unpronounceable gibberish into easily understandable language. He also has written for a variety of online publications, including HuffPost, The Method, Tincture and Angry Scientists, and is passionate about topics ranging from mental health to the social determinants of our society.
You can follow him on Twitter @GidMK or at or Facebook.
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