(p. C3) So how should we approach risk? The numbers can help, especially if we simplify them. For acute risks, a good measure is the MicroMort, devised by Stanford’s Ronald A. Howard in the 1970s. One MicroMort (1 MM) is equal to a one-in-a-million chance of death.
. . .
In truth, “Don’t do that, it’s dangerous!” is about much more than the numbers. We must also reflect on the full basis for our preferences–such as, to take one small psychological characteristic among many, what we value in life, as well as what we fear.
. . .
In fact, the numbers tend to have the effect of highlighting the psychological factors. Take traveling. For 1 MM, you can drive 240 miles in the U.S., fly 7,500 miles in a commercial aircraft or fly just 12 miles in a light aircraft. We tend to feel safer if we feel more personal control, but we have no control whatsoever in a passenger jet, the safest of all (notwithstanding last week’s terrible tragedy). You could take that as evidence of human irrationality. We take it as evidence that human motives matter more than the pure odds allow.
For the full commentary, see:
MICHAEL BLASTLAND and DAVID SPIEGELHALTER. “Risk Is Never a Strict Numbers Game; We tell children to shun ecstasy but don’t fret about horseback riding–and other foibles of our view of danger.” The Wall Street Journal (Sat., July 19, 2014): C3.
(Note: ellipses in original.)
(Note: the online version of the commentary has the date July 18, 2014.)
The passages quoted above were from a commentary adapted from the book:
Blastland, Michael, and David Spiegelhalter. The Norm Chronicles: Stories and Numbers About Danger and Death. New York: Basic Books, 2014.