ABSTRACT
One amazing thing about this vignette, in addition to its long-standing popularity and compelling results, is the confidence with which the forecasts are announced. Some authority seems to know that in this particular “unusual” outbreak exactly 600 American citizens will die. No more, no less. Then two programs are announced, again with guaranteed outcomes: in Program A, 200 will be saved; in B, there is a 13 probability of saving all 600 and a 23 probability of saving none. How do we know? Program A is often described as the “sure” or “riskless” option, indicating that no uncertainty is involved. Program B is even more amazing by stating not only the exact numbers of victims and survivors, but also the exact probabilities of these outcomes.
