Larry Fink, founder and chief executive of BlackRock, the biggest asset management firm in the world, is worried about longevity.

While the fact that we are all living longer is considered an unalloyed positive, Fink is concerned we have not fully adjusted to the effects on our economy - and on our personal finances. "We need to grasp the effects of longer lives, on the markets, on employment and on the need to save for retirement," he said.