People are not really great at assessing probabilities. That’s why we have irrational fears and why we tend to overestimate our odds of winning the lottery. When I have to travel by plane, for instance, my palms get sweaty, my heart starts racing, and my thoughts take a turn for the worse. It’s weird because I should actually be more worried when I hop on my bike in Darmstadt, Germany, where I live. Statistically speaking, I’m in much more danger on the road than up in the air. But for some reason, my bike commute doesn’t stress me out at all.
A buddy of mine recently mentioned a concept in decision theory that is supposed to help people better understand hazards and risks. Back in 1980, an electrical engineer named Ronald Arthur Howard came up with the micromort unit to measure life-threatening danger. One micromort equals a one-in-a-million chance of kicking the bucket during a particular activity. Want to run a marathon? That’s seven micromorts. Going under general anesthesia? That’ll cost you 10 micromorts. But here’s the catch – you need a bunch of detailed statistics to come up with these numbers. How many folks did these activities and end up biting the dust? And the results can vary a lot based on the group of people being studied (like their age, gender, and so on), as well as where they are located.
Better Living through Statistics
It’s kinda surprising, but the history of statistics isn’t that old. Back in the 17th century, a British demographer named John Graunt started looking into mortality statistics by checking out records of deaths and baptisms. But it wasn’t until 200 years later that society really grasped the benefits of these approaches. Nowadays, statistics are all the rage. Insurance companies and banks use them to figure out risks. Statistical surveys help us dig into psychological and sociological phenomena. And physical research would be a total mess without statistics. Thanks to Howard and the micromort, we can now estimate the risks in our daily lives using stats. By looking at how many people die while doing a certain activity, he was able to come up with an overall mortality risk for those activities.
But more recently, a mathematician named David Spiegelhalter realized there was something missing in Howard’s analysis: the micromort unit only tells us how likely a specific action is to kill us. This might make sense for a one-time activity like climbing a mountain. But for long-term habits, like chowing down on fast food regularly, the measure doesn’t really cut it. For example, smoking a cigarette gives you just 0.21 micromort, which means it’s way less risky than getting out of bed in the morning when you’re 45 years old (that’s six micromorts). But smoking has some serious long-term effects on your body that just getting out of bed doesn’t have. So the long-term risk isn’t really accounted for. Spiegelhalter came up with the “microlife” measure to consider the long-term effects of different activities. This helps us figure out how much life we’re losing on average by doing certain things. Each microlife lost shaves off half an hour from your life expectancy. For instance, two hours of TV a day could cost you one microlife.
