David Brindle: [$40 trillion] is the estimated amount in pension funds and life insurance policies that is vulnerable if actuaries have got their sums wrong and people live significantly longer than anticipated. Given the quite astounding things that are happening with life expectancy, it's almost certain that they will.
Until about 1975, life expectancy of men in their 70s in the UK was improving at a steady rate of about 0.5% a year. Since then, it has rocketed to an annual rate of more than 4%. According to Richard Willets, longevity director of insurer Paternoster, actuaries' estimates of male life expectancy at retirement have "probably changed more in the past 10 years than in the previous 100".