Even if that extra capital is not put to work  13  Some modelling work I did with colleagues at the Bank a few years ago showed that, under plausible assumptions, an optimal response to ageing would see a rise in savings and a rise in the ratio of capital to labour; see Kulish M, C Kent and K Smith (2010) for details.
More savings allow the capital stock to rise at the same time as the share of population working declines. People work more years of their lives, in part to help them build up their savings. Nevertheless, they need not spend a greater share of their lives working.