Features Australia

Odds are they aren’t

Today’s politicians ignore statistical probabilities

6 June 2020

9:00 AM

6 June 2020

9:00 AM

People aren’t good at thinking about probabilities. Our brains didn’t evolve to think that way and so you have to learn to do so. My first degree was in mathematics and my favourite class was probability. It was so counter-intuitive. I still recall the time the professor walked in and asked us ‘how many people do you need in a room to have a 50-50 chance of two of them sharing the same birthday (not the same year, but the day of the year)?’. I have long since forgotten the three classes of work we spent proving the answer from first principles, but I’ve never forgotten the answer itself.  It’s ‘23’. Put 40 in a room and you get up near a 90 per cent chance of two or more shared birthdays. At 75 people it’s very close to 100 per cent.

But that intuitively strikes almost all of us as wrong. That lack of facility in handling probabilities is why there’s this gleaming new city in the desert called Las Vegas. Go there and have fun but you’ll never play a game against the house where you have close to a 50-50 chance of winning, whatever ‘system’ you may employ. Well, unless you can count seven or eight decks of cards at blackjack and hide the fact you’re doing so – because you can gain enough information doing that to give yourself the odd chance that’s better than even. Good luck trying.

I bring this up because it bears on two things in the news right now. Start with the Minneapolis death of George Floyd with the police officer kneeling on the side of the man’s neck. If you’ve watched the video taken of this it’s ghastly. The man is pleading that he can’t breathe and yet the officer won’t get off his neck – and the man is handcuffed at the time so no threat to anyone. God it looked terrible – a white policeman heartlessly kneeling on a black man’s throat. And the black man dies.

But then the medical examiner has now reported that Floyd did not die of asphyxia or strangulation and, astoundingly, there is some question about whether this was what the police were trained to do. Still, looks like pretty immoral conduct to me.


But in light of all the days of rioting across the US if you ask people to put this in context I bet almost all of them would get it wrong. It instinctively feels as though lots of white cops are killing lots of black men in the US. But that’s not true. The Washington Post (a lefty, liberal rag if ever there were one) has a database that lists the stats for 2018. Seventeen unarmed blacks were killed by police that year. Assume every one was by a white cop (probably not true) and that every one was an unjustified killing (also probably false). Even on those assumptions that adds up to about 0.2 per cent of black homicide victims for 2018. By contrast, 90 per cent of those deaths were killings of blacks by other (non-police) blacks.

And likewise if you asked people what percentage of all police killings were of blacks, and they had only the mainstream media’s reporting to go by, they’d get this one wrong too. You see just under three-quarters of police killings in the US each year are not of blacks. But when do you hear a report of the police killing a white guy or Asian? Not often. Okay, maybe if the victim were gay or Muslim or Democrat or fitted into some other category the press likes to paint as victims.

None of this is an apologia for the cop in the Floyd case. The guy was a heartless prick. He deserved to be fired immediately, as he was. And the bystander cops too for cowardice. It is a slam dunk for manslaughter. Nor am I here giving a defence of the US criminal justice system. I’m just about the most pro-American non-American law professor in Christendom. But the US criminal justice system is awful. At the federal level they terrorise and plea bargain people into pleading guilty – indeed as Conrad Black and Mark Steyn point out regularly the federal prosecutors there have a 99 per cent success rate, up there with China’s.

But that doesn’t change how warped most people’s views of the relative likelihoods of police killings of blacks are. Indeed this is why the LeBron James, Colin Kaepernick ‘taking a knee’, sports stars against supposed police brutality campaign is basically stupid. They are generalising from a handful of reported cases. They don’t know the facts. Worse, they’re missing the real problem with US criminal justice while they bask in the warm glow of their own virtue-signalling.

And then, the second current news issue where probabilities matter is the Wuhan flu (I’m not going to be cowed on the name) and the merits of the lockdown. Remember Sweden where the government shunned the lockdown? The press goes into spasms of glee trying to paint the situation there as awful. Well, as of writing 99.998 percent of Swedes have not died from the Communist Party of China virus (ditto). Only a relatively tiny (if we’re honest) 4,350 have. Statistical analyses of countries that locked down and those that didn’t cannot find any meaningful difference – well, except that the non-lockdown jurisdictions kept their economies ticking over. Plus, the press continually glosses over the reality that this virus hits the old with existing serious illnesses, not the young. If you’re under 20 you have a 15 times or more chance of dying from the regular flu. If you’re under 40 it’s a toss-up whether a lightning strike is more likely to take you out than the Wuhan virus. In Pennsylvania more people over 100 have died of the virus than those under 45; more over 95 than under 60; and more over 85 than under 80. Florida is much the same.

Every time you read or hear any report about this virus on the ABC or any press outlet ask yourself – because they won’t tell you – how many comparable deaths were there last year of the flu?  (Note: in 34 US states more people died of the 2018 flu than so far of this China virus, and no one locked down anything in 2018.) How many people usually die in my country in a year, or a day? (Aussie answers: 161,000 and 441.) Where does Wuhan fit in as a cause of death? (Doesn’t break the top 50 in Australia. Seriously.) What will the likely deaths be because of these lockdowns? (Bad, really bad, not to mention the young will bear the brunt economically.)

If you ask some of those questions you can join me as a lockdown sceptic and we can start to put some pressure on our woeful politicians to open up the economy now. Immediately. God knows the only probabilities they get are ones related to their re-election prospects.

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