Is it worth taking a 1 in 100,000 chance of dying , in order to experience the novel thrill of sky diving? Is a 1 in 500,000 chance of death worth it to go bungee jumping?
It’s hard to know whether these risks are reasonable, because numbers like 100,000 or 500,000 feel so abstract to us. To think more clearly about these numbers, it helps to get our intuitions engaged.
We can start by figuring out the daily risk of dying that we automatically face every day. My “death calculator” tool above will compute yours, as estimated from your gender and age. For instance, in the United States, a 30 year old man has about a 1 in 260,000 chance of dying tomorrow whereas a 30 year old woman has about a 1 in 583,000 chance. A 55 year old man has a 1 in 46,000 chance of dying on any given day and a 55 year old woman a 1 in 79,000 chance. Note that while it’s extremely difficult to estimate a person’s life span (since future technological and societal changes may radically alter how long people live), estimating how likely a person is to die in the next day is much more accurate and straightforward.
Once you’ve used the tool to calculate your own chance of dying tomorrow, you can start thinking about the risk of dangerous activities relative to how much risk you already take each day (merely by going about normal activities). In particular, you can calculate how many total days worth of risk an activity involves. So for instance, if you are a 30 year old male, and ride 100 miles on a motorcycle tomorrow, then you’ll experienced 11.2 days worth of risk of dying tomorrow, rather than a single normal day of risk.
To do the calculation of how many days of risk you’re taking in a day where you do the dangerous activity, simply calculate the following: Start with the probability that you die in a normal day, add to it the probability that you die from doing the risky activity, and then divide the result by the probability that you die in a normal day.
So for instance, if you were to go BASE jumping tomorrow (an activity that appears to have about a 1 in 2,300 chance of death), and if you normally have a 1 in 100,000 chance of dying in a given day (for instance, you’re a 46 year old man) then you’d be taking on ((1/2300)+(1/100000))/(1/100,000) = 44.5 days worth of ordinary daily risk tomorrow, instead of just 1 day of risk.
Would that be worth it? For some people, it might be possible it is worth BASE jumping once in their in life. But suppose you were to go BASE jumping 20 times over the next year, on 20 different days. Then rather than consuming 365 days of typical risk that year (as a 46 year old man), you’d be taking on about 1235 days worth of risk, an additional roughly 2.4 years of risk! It’s hard to imagine that being worth it, even if BASE jumping is incredibly enjoyable. Of course, there is also a high risk of injury, aside from the risk of death.
Below is a table with estimates of the chance of dying from doing various activities.
Taking a 340 mile road trip on occasion with friends seems very reasonable. For instance, a 30 year old male will only be doubling his risk of dying that day, and a 30 year old female will be taking on about 3.3 days of her usual daily risk. But taking a job as a taxi driver in a suburban area or a long distance courier, driving 340 miles most days, would be much more risky. A 30 year old male who took such a job would be doubling his risk of dying every day. Another way to think about it is that despite being a 30 year old male, he would living with the daily risk of a 43 year old male. Similarly, a 30 year old male who decided to go BASE jumping one day, would be living that day with the daily risk of death of an 88 year old man.
So what risks are worth taking? It’s ultimately a subjective question. But thinking in terms of how much you’re increasing your ordinary daily risk, and converting risks into the daily risk of people of different ages, can make these abstract numbers more intuitive. And stronger intuition can help us reason more sanely about our choices.
Disclaimer: these numbers come from the internet, so if you want to be confident about any of them, you should double check them using a reliable source. Note also that actual death rates will depend on a variety of factors, including the amount of experience you have doing that activity and the location where you are doing it. Furthermore, note that for many of these activities there are risks of injury, in addition to risk of death, but I’ve only considered risk of death in this analysis. Be very cautious before deciding to engage in any dangerous activity!
|Activity||1 in __ chance of dying||per||Days of risk (30 yr male)||Days of risk (30 yr female)|
|Driving 100 miles on a motorcycle||26,000||100 miles driven||11.2||23.7||source|
|Participating in a triathlon||67,000||run||4.9||9.7||source|
|Running a marathon (cardiac arrest)||127,000||run||3.1||5.6||source|
|Driving 100 miles in a car||877,000||100 miles driven||1.3||1.7||source|
|Flying 1,000 miles in a commercial airplane in the U.S.||3,333,000||1,000 miles flown||1.1||1.2||source|