Consider Julian Simon, a population and natural resource optimist, who found that he could not compete for either popular or academic attention with best-selling doomsayers like Paul Ehrlich. In 1980 Simon challenged Ehrlich to bet on whether the price of five basic metals, corrected for inflation, would rise or fall over the next decade. Ehrlich accepted, and Simon won, as would almost anyone who bet in the same way in the last two centuries. This win brought Simon publicity, but mostly in the form of high-profile editorials saying ‘Yeah he won this one, but I challenge him to bet on a more meaningful indicator such as …’. In fact, however, not only won’t Ehrlich bet again, although his predictions remain unchanged, but also none of these editorial writers will actually put their money where their mouths are! In addition, the papers that published these editorials won’t publish letters from Simon accepting their challenges.

Robin Hanson, ‘Could Gambling Save Science? Encouraging an Honest Consensus’, Social Epistemology, vol. 9, no. 1 (1995), p. 8