Bentham's Bulldog Stands With Caplan

His critics are confused, unless Bryan secretly loves hanging out near rusty nails

I might be the world’s leading critic of

Bryan Caplan

. I’ve written many different articles about why Caplan is wrong (bunch of links there, not just two), and have debated him about the existence of God. My disagreements with Caplan have been interesting and wide-ranging—while I think he’s often wrong, Caplan is quite smart and actually gives reasons for the things he believes, leaving himself open to critique (unlike, say, the typical continental philosopher who writes in an incomprehensible web of text that makes it impossible to figure out what the hell they’re saying!) My disagreements with Caplan have led to one serious error on my part: in an article arguing that one shouldn’t ultimately be non-instrumentally risk averse, I titled it “contra Caplan on continuous contentment.” Fool! It should have been “Contra Caplan Concerning Continuous Contentment.” I. Will. Do. Better.

Caplan has become the main character of the day on Twitter. Lots of people are taking the chance to dunk on him. Now, I’m all for dunking on Caplan, but if one is going to do so, they should dunk on one of his false views, not one of his true ones. Unfortunately, people on Twitter have been getting outraged about one of his true views:

Come on, take into account relative risk! In fact, you’re about as likely to die on the way to get the tetanus shot than you are of tetanus. The average person drives about an hour a day. The odds of dying in a car accident over the course of your life is about 1 in 93 (yikes, that’s high!) There are 21,915 days in 60 years (about how long people will be driving for), meaning that after 21,915 hours of driving roughly, there’s a 1 in 93 chance you’ll die. Dividing (1/93) by 21,915 means the odds of dying per hour of driving are 4.90654263x10^-7. If we assume it takes a half hour to drive to the appointment, this means that you’re odds of 2.45327131x10^-7. So it’s about 1 in 3 million. In contrast, about 2 people die a year of tetanus. About a third of people aren’t boosted, so maybe 6 people in the U.S. would die if no one got boosted (by massively inflated assumptions. Per year, therefore, the excess odds of a person dying are on the order of 1.80018002 x 10^-7. So if these numbers are right, you’re more likely to die from a car accident on the way to get the booster than you are from tetanus.

Sure, maybe some people get tetanus but don’t die of it. But a sizeable portion of those who get it die, so the number of people seriously suffering from it in the U.S. is on the order of 10. It’s not worth it to engage in a painful choice to reduce one’s risk of death or injury by quite a bit less than 1 in a million.

It makes sense to get a COVID vaccine. It even makes sense to get a COVID booster. The Tetanus vaccine is really important in poor countries with poor sanitation. But it makes no sense to undergo costs to reduce risks on the order of getting struck by lightning. Bryan wrote an article laying this out too:

Tetanus and Medical Innumeracy

Twitter, of course, was not won over by Bryan’s ironclad reasoning, displaying the typical level of snark and confusion. I will go through all the top Tweets responding to Caplan and explain why they are all wrong. I am doing this for one simple reason: Twitter promotes being snarky even if one is completely and totally wrong, and this is irritating. It’s worth correcting obvious bullshit.

In this above comic, the person is reasoning poorly because, though lightning kills few people in general, that’s the wrong reference class. It kills a large share of the people who remain outside in lightning storms and don’t act cautiously. But this is not like Tetanus, which does not kill a large percentage of the unboosted. A third of people are unboosted. It kills two people a year! More people die annually from vending machines than Tetanus.

It would be one thing if Bryan liked to hang out next to bacteria-coated rusty construction sites, but he doesn’t. Brian is less likely to be killed than the average unboosted person from Tetanus.

19,000 people found this funny and clever enough to like the Tweet! Is there no justice? Once again, the disanalogy is that the vast majority who fall out of planes without a parachute (all of them?) die. In contrast, the vast majority of people who are unboosted do not die! This isn’t hard!

4,100 people thought this was a good point. But there’s an obvious disanalogy: there’s herd immunity for Polio. The primary reason to get a Polio vaccine is that if a lot of people don’t, really bad things happen. In contrast, Tetanus is not contagious, and there’s no herd immunity. If 10% of the population didn’t get Polio shots, there’d likely be an epidemic. If 10% of the population didn’t get Tetanus boosters, there wouldn’t be.

It’s just all like this—lots of snark but points so bad that three seconds of thought is enough to dispel them!

It’s always strange finding out that people you thought were on your team are really deeply crazy. I’m in favor of vacccines because they produce quite significant benefit at comparatively minor cost, not just because they’re called vaccines and doctors generally recommend them. It seems that a lot of people’s support for vaccines is a result purely of the fact that they’re called vaccines and that doctors tend to recommend them.

Usually, it’s the anti-vaxxers that are statistically illiterate and make terrible arguments. In this case, however, the flip side is true, and those criticizing Caplan are the ones being statistically illiterate. This is a danger of tribalism—if you make trusting the science a core feature of your identity, you’ll acquiesce to utterly ridiculous claims that are seen as the establishment view.