ABSTRACT
Before plunging headlong into controversy, I want to make some (hopefully) non-controversial remarks about forecasting. It is common for writers who disparage the activity to note that prediction is difficult, ‘especially as concerns the future’. 1 Isaac Asimov’s Foundation novels feature a psychohistorian genius named Hari Seldon, who has developed a probabilistic theory of social systems. An early scene has Seldon demonstrating to a young research assistant that there is a probability of 92.5 per cent that the galactic empire will collapse into anarchy within 500 years (Asimov, 1951). The notion that any such prediction could be made from a set of mathematical symbols has always tickled my funny bone.
