William MacAskill

“When thinking about risk from transport, you can think directly in terms of minutes of life lost per hour of travel. Each time you travel, you face a slight risk of getting into a fatal accident, but the chance of getting into a fatal accident varies dramatically depending on the mode of transport. For example, the risk of a fatal car crash while driving for an hour is about one in ten million (so 0.1 micromorts). For a twenty-year-old, that’s a one-in-ten-million chance of losing sixty years. The expected life lost from driving for one hour is therefore three minutes. Looking at expected minutes lost shows just how great a discrepancy there is between risks from different sorts of transport. Whereas an hour on a train costs you only twenty expected seconds of life, an hour on a motorbike costs you an expected three hours and forty-five minutes. In addition to giving us a way to compare the risks of different activities, the concept of expected value helps us choose which risks are worth taking. Would you be willing to spend an hour on a motorbike if it was perfectly safe but caused you to be unconscious later for three hours and forty-five minutes? If your answer is no, but you’re otherwise happy to ride motorbikes in your day-to-day life, you’re probably not fully appreciating the risk of death.”
― William MacAskill, Doing Good Better: How Effective Altruism Can Help You Make a Difference