Economic uncertainty – as reflected, for example, in stock market volatility – rose dramatically. The unpredictability of rare events highlights an important distinction between “risk” and “uncertainty”, which was first made by the famous economist Frank Knight in 1921. According to Knight, “risk” refers to a situation of randomness where the range of possible events and the associated probability distribution are known.
This increase is arising, not from increasing fertility which has been steadily declining from 2.05 to 1.5 over the last ten years, but rather from our longer life expectancy which has increased by 2 years for both males and females to stand at 69.5 and 76.6, respectively, over the same  4  BIS Review 161/2010  period.