The unsurprising confusion about ‘per capita’
A car cut me off on the highway the other day. The car was going nearly 100 mph.
Was the car a new Porsche 911 GT3 or a used Toyota Camry?
The thing is, there are more than 1,000 times as many Camrys on the road. But our instinct is to pick the vivid and distinctive answer.
The per capita crime rate in rural areas is often dramatically (sometimes five or ten times) higher than it is in most cities.
On the other hand, Alaska has far more millionaires per capita than most people would guess. That’s because we underestimate the population, not because there’s a particularly large number of millionaires.
More people might lead to more instances, but what matters isn’t the absolute number, it’s the percentage. New York is an incredibly safe place to live.
We’re simply not naturally attuned to dividing what we notice by the chances we’ll see it… stories resonate without regard for the denominator.
Flying across the country is dramatically safer than driving there, but intuitively, it feels like the opposite must be true. And peer-reviewed medicine is far more likely to cure an illness than an anecdote will.
The average TikTok or Facebook post is seen by just a few people, even though it feels like the ones we’re seeing are seen by a lot of people.
Reality is lumpy, and taking a moment to think about the source of our story helps us get clear about what’s actually happening.